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Selegiline is an irreversible, selective type-B monoamine oxidase inhibitor (MAOI) approved for Parkison's disease-oral and major depressive disorder-transdermal formulation) result-ing in non-selective MAOI activity at oral doses >20 mg/day. The present systematic re-view and meta-analysis appraises the evidence of different formulations/dosages of selegiline across different psychiatric conditions. We inquired PubMed/MEDLINE/Cochrane-Central/WHO-ICTRP/Clarivate-WebOfScience and the Chinese-Electronic-Journal Database from inception to 10/26/2022 for selegiline trials involving psychiatric patients. Random-effects meta-analyses assessed heterogeneity, publication/risk biases, and confidence in the evidence, followed by sensitivity, subgroup, and meta-regression analyses. Co-primary outcomes were: changes in symptom score (standardized mean difference =SMD) and author-defined response (risk ratios =RRs). RRs of adverse events and all-cause discontinuation were secondary and accept-ability outcomes, respectively. Systematic-review included 42 studies; meta-analysis, 23. Se-legiline outperformed placebo in depressive symptom reduction (SMD=-0.96, 95%C.I.=-1.78,-0.14, k = 10, n = 1,308), depression (RR = 1.61, 95%C.I. = 1.20, 2.15, k = 9, n = 1,238) and atypical-depression response (RR = 2.23, 95%C.I. = 1.35, 3.68, k = 3, n = 136). Selegiline failed to outperform the placebo in negative ( k = 4) or positive symptoms of schizophrenia ( k = 4), attention-deficit-hyperactivity disorder (ADHD) symptoms reduction ( k = 2), and smoking ab-stinence rate ( k = 4). Selegiline did not differ from methylphenidate and ADHD scores ( k = 2). No significant difference emerged in acceptability, incident diarrhea, headache, dizziness, and nausea RRs, in contrast to xerostomia (RR = 1.58, 95%C.I. = 1.03, 2.43, k = 6, n = 1,134), insom-nia (RR = 1.61, 95%C.I. = 1.19, 2.17, k = 10, n = 1,768), and application-site reaction for trans -dermal formulation (RR = 1.81, 95%C.I. = 1.40, 2.33, k = 6, n = 1,662). Confidence in findings was low/very-low for most outcomes; moderate for depressive symptoms reduction (transder-mal). Selegiline proved effective, safe, and well-tolerated for depressive disorders, yet further evidence is warranted about specific psychiatric disorders.(c) 2023 Elsevier B.V. and ECNP. All rights reserved.

While verbal memory is among the most compromised cognitive domains in schizophrenia (SZ), its neural substrates remain elusive. Here, we explored the structural and functional brain network correlates of verbal memory impairment in SZ. We acquired diffusion and resting-state functional MRI data of 49 SZ patients, classified as having preserved (VMP, n = 22) or impaired (VMI, n = 26) verbal memory based on the List Learning task, and 55 healthy controls (HC). Structural and functional connectivity matrices were obtained and analyzed to assess associations with disease status (SZ vs. HC) and verbal memory impairment (VMI vs. VMP) using two complementary data-driven approaches: threshold-free network-based statistics (TFNBS) and hybrid connectivity independent component analysis (connICA). TFNBS showed altered connectivity in SZ patients compared with HC (p

The prevalence, correlates, and management of tobacco use disorder (TUD) or nicotine dependence (ND) among people with severe mental illness (SMI), namely schizophrenia, bipolar disorder (BD), and major depressive disorder (MDD), remain unclear. Therefore, a systematic review and meta-analysis was conducted. Electronic databases were systematically searched from inception to July 12, 2020, for observational studies documenting the prevalence, odds, and correlates of TUD/ND among people with SMI; randomized controlled trials (RCTs) informing the management of TUD/ND in people with SMI were also included. Random-effects meta-analyses were conducted. Sources of heterogeneity were explored. Nineteen observational studies, including 7527 participants with SMI met inclusion criteria. TUD/ND co-occurred in 33.4-65% of people with SMI. Rates were higher among males. While bupropion and varenicline represent promising treatment opportunities for schizophrenia with TUD/ND, non-pharmacological interventions require further research, mainly for people with primary mood disorders. TUD/ND represent prevalent co-occurring conditions among people with SMI. Further well-designed RCTs are warranted to inform their management.

Aim Early age at schizophrenia onset (EOS) has been associated with a worse clinical course, although previous studies reported substantial heterogeneity. Despite the relevance of the subject, the relationship between the age of onset and treatment resistant schizophrenia (TRS) is less clear. Methods We screened 197 non-affective psychotic patients. Of these, 99 suffered from schizophrenia and were putative TRS and were included in a prospective 4-to-8-week trial to assess their response to antipsychotics. According to status (TRS/nonTRS) and age-at-onset (early: ≤18 years, EOS; adult: >18 years, adult onset schizophrenia [AOS]) patients were subdivided in EOS-TRS, EOS-nonTRS, AOS-TRS, AOS-nonTRS. Multiple clinical variables were measured and compared by analysis of covariance (ANCOVA), using age as a covariate. Two-way analysis of variance (ANOVA) was used to assess whether significant differences were attributable to TRS status or age-at-onset. Results The rate of TRS patients was significantly higher in EOS compared to AOS. At the ANCOVA, EOS-TRS had significantly worse clinical, cognitive, and psychosocial outcomes compared to the other groups. Overall, EOS-TRS were more impaired than EOS-nonTRS, while significant differences with AOS-TRS were less consistent, albeit appreciable. Two-way ANOVA demonstrated that, in the majority of the investigated variables, the significant differences among groups were attributable to the TRS status effect rather than to age-at-onset or combined effects. Conclusions These results suggest that refractoriness to antipsychotics may be strongly linked to the early onset of psychotic symptoms, possibly as a result of common neurobiology.

Cariprazine is a novel antipsychotic drug that exerts partial agonism of dopamine D2/D3 receptors with preferential binding to the D3 receptor, antagonism of 5HT2B receptors, and partial agonism of 5HT1A. Currently, cariprazine has shown clinical efficacy in patients with schizophrenia and with bipolar disorder, as well as adjunctive treatment in patients with Major Depressive Disorder (MDD) and drug-resistant MDD. In the present case series, we report on two patients with treatment-resistant schizophrenia and partial response to clozapine who benefit from combination with cariprazine. The effects of cariprazine combination were remarkable also concerning the adverse metabolic effects of clozapine.

Treatment resistant schizophrenia (TRS), the lack of response to at least two antipsychotics administered at adequate dose and duration, epitomizes in psychiatry one of the most difficult-to-treat pathologies, epidemiologically relevant (affecting one-third of schizophrenia patients) and with severe consequences for the patients in terms of overall functioning. After 50 years, only one drug is approved for TRS: clozapine. Furthermore, a few patients do not respond even to clozapine and are indicated as clozapine-resistant patients. In this review and expert opinion, we have critically appraised the current literature, discussing the role of old and new agents in treating resistant schizophrenia. The search for therapy against TRS, beyond clozapine or in addition to clozapine, has emerged over time, capturing mainly three types of strategies: 1. Add-on of a second-generation antipsychotic (i.e. amisulpride); 2. Add-on of a second antipsychotic with significantly different receptor profile compared to the older ones (e.g. aripiprazole and cariprazine); 3. Novel strategies beyond dopamine D2/D3 receptor occupancy (e.g. xanomeline + trospium, TAAR1-agonists, sodium benzoate, and D-amino acids). More high-quality clinical trials applying the current operationalized criteria for TRS and clozapine-resistance are required to evaluate the efficacy of alternative and add-on treatments.

Background: Treatment-resistance in schizophrenia is 30–40%. Its neurobiology remains unclear; to explore it, we conducted a combined spectrometry/tractography/cognitive battery and psychopathological rating study on patients with treatment-resistant schizophrenia (TRS), dividing the sample into early-onset (N = 21) and adult-onset TRS (N = 20). Previous studies did not differentiate between early- (onset 13–18 years) and adult-onset (>18 years at formal diagnosis of schizophrenia) TRS. Methods: We evaluated cross-sectionally 41 TRS patients (26 male and 15 female) and 20 matched healthy controls (HCs) with psychopathological and cognitive testing prior to participating in brain imaging scanning using magnetic resonance spectroscopy and diffusion tensor imaging to determine the relationship between their symptoms and their glutamate levels and white matter integrity. Results: TRS patients scored lower than HCs on all cognitive domains; early-onset patients performed better than adult-onset patients only on the Symbol Coding domain. TRS correlated with symptom severity, especially negative symptoms. Glutamate levels and glutamate/creatine were increased in anterior cingulate cortex. Diffusion tensor imaging showed low fractional anisotropy in TRS patients in specific white matter tracts compared to HCs (bilateral anterior thalamic radiation, cortico-spinal tract, forceps minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, and right uncinate fasciculus). Conclusions: We identified specific magnetic resonance spectroscopy and diffusion tensor imaging alterations in TRS patients. Adult-onset TRS differed little from early-onset TRS on most measures; this points to alterations being present since the outset of schizophrenia and may constitute a biological signature of treatment-resistance.

There is a growing interest in new molecular targets for antipsychotic therapy. Multiple signal transduction systems have been recently implicated in the pathophysiology of schizophrenia. However, the weight of each specific mechanism remains controversial. A need for a more vigorous approach to the pharmacotherapy of schizophrenia arises from the bedside: about 30-40% of patients do not respond to antipsychotic therapy. Postsynaptic Density (PSD) proteins have recently attracted attention for their role in signal transduction modulation and for their potential implication in psychosis and cognition. The involvement of PSD in the pathophysiology of schizophrenia is supported by post mortem studies, preclinical animal models, modulation by antipsychotics, and association of PSD genes with schizophrenia in GWAS. Taken together, these studies underline the role of PSD modulation, its effects on striatal function and its relationship with motor, executive- and cognitive-like functions suggesting a potential role of PSD proteins as a l target of novel intervention in the treatment of refractory psychosis.

Once considered only scaffolding proteins at glutamatergic postsynaptic density (PSD), Homer1 proteins are increasingly emerging as multimodal adaptors that integrate different signal transduction pathways within PSD, involved in motor and cognitive functions, with putative implications in psychiatric disorders. Regulation of type I metabotropic glutamate receptor trafficking, modulation of calcium signaling, tuning of long-term potentiation, organization of dendritic spines’ growth, as well as meta- and homeostatic plasticity control are only a few of the multiple endocellular and synaptic functions that have been linked to Homer1. Findings from preclinical studies, as well as genetic studies conducted in humans, suggest that both constitutive (Homer1b/c) and inducible (Homer1a) isoforms of Homer1 play a role in the neurobiology of several psychiatric disorders, including psychosis, mood disorders, neurodevelopmental disorders, and addiction. On this background, Homer1 has been proposed as a putative novel target in psychopharmacological treatments. The aim of this review is to summarize and systematize the growing body of evidence on Homer proteins, highlighting the role of Homer1 in the pathophysiology and therapy of mental diseases.

Background Although extensively studied, the effect of antipsychotics is not completely understood at a network level. We tested the hypothesis that acute administration of haloperidol would modulate functional connectivity of brain regions relevant to schizophrenia pathophysiology. To assess putative changes in brain network properties and regional interactivity, we studied the expression of Homer1a, an Immediate Early Gene (IEG) demonstrated to be induced by antipsychotic administration and coding for a protein involved in glutamatergic synapses remodeling. Methods Sprague-Dawley rats (n = 26) assigned to vehicle (VEH; NaCl 0.9%) or haloperidol (HAL; 0.8 mg/kg) were included in the network analysis. Homer1a mRNA induction was evaluated by in situ hybridization. Signal intensity analysis was performed in 33 Regions of Interest (ROIs) in the cortex, the caudate putamen, and the nucleus accumbens. A signal correlation analysis was performed, computing all possible pairwise Pearson correlations among ROIs in the two groups. Two networks were generated for HAL and VEH groups, and their properties and topography were explored. Results VEH and HAL networks showed qualitative differences in global efficiency and clustering coefficient. The HAL network showed enhanced interactivity between cortical and striatal regions, and within caudate putamen subdivisions. On the other hand, it exhibited reduced inter-correlations between cingulate cortex and anterior insula and caudate putamen and nucleus accumbens. Moreover, haloperidol was able to modulate centrality of crucial functional hubs. These preclinical results corroborate and expand the clinical evidence that antipsychotics may modulate specific brain network properties and disease-related circuits’ interactivity.

ADHD, schizophrenia and bipolar disorder are psychiatric diseases with a strong genetic component which share dopaminergic alterations. Dopamine transporter (DAT) genetics might be potentially implicated in all these disorders. However, in contrast to DAT absence, the effects of DAT hypofunction especially in developmental trajectories have been scarcely addressed. Thus, we comprehensively studied DAT hypofunctional mice (DAT+/-) from adolescence to adulthood to disentangle DAT-dependent alterations in the development of psychiatric-relevant phenotypes. From pre-adolescence onward, DAT+/- displayed a hyperactive phenotype, while responses to external stimuli and sensorimotor gating abilities were unaltered. General cognitive impairments in adolescent DAT+/- were partially ameliorated during adulthood in males but not in females. Despite this, attentional and impulsivity deficits were evident in DAT+/- adult males. At the molecular level, DAT+/- mice showed a reduced expression of Homer1a in the prefrontal cortex, while other brain regions as well as Arc and Homer1b expression were mostly unaffected. Amphetamine treatments reverted DAT+/- hyperactivity and rescued cognitive deficits. Moreover, amphetamine shifted DAT-dependent Homer1a altered expression from prefrontal cortex to striatal regions. These behavioral and molecular phenotypes indicate that a genetic-driven DAT hypofunction alters neurodevelopmental trajectories consistent with ADHD, but not with schizophrenia and bipolar disorders.

Objectives The postsynaptic density (PSD) represents a site of dopamine-glutamate integration. Despite multiple evidence of PSD involvement in antipsychotic-induced synaptic changes, there are no direct head-to-head comparisons of the effects at the PSD of antipsychotics with different receptor profile and at different doses after chronic administration. Methods Molecular imaging of gene expression was used to investigate whether chronic treatment with first and second generation antipsychotics (haloperidol, asenapine and olanzapine) may induce changes in the expression levels of PSD transcripts involved in schizophrenia pathophysiology, i.e. Homers , Shank1 , PSD-95 and Arc . Results Genes' expression patterns were differentially modulated after chronic administration of typical and atypical antipsychotics as well as by the same compound administered at different doses. Antipsychotic treatment reduced gene expression in cortical regions, while Homer1a was still induced in striatum by haloperidol even after prolonged treatment. Moreover, chronic treatments appeared to cause a “de-recruitment” of brain regions demonstrated to be activated in acute treatments, with a prominent effect in the cortex rather than in striatum. Conclusions These results let hypothesize that prolonged antipsychotic treatment may trigger a set of plastic changes involving scaffolding and effector molecules causing a possible re-arrangement of PSD transcripts in brain regions relevant to schizophrenia pathophysiology.

In this study, we investigated whether minocycline, a second-generation tetracycline proposed as an add-on to antipsychotics in treatment-resistant schizophrenia (TRS), may affect the expression of Homer and Arc postsynaptic density (PSD) transcripts, implicated in synaptic regulation. Minocycline was administered alone or with haloperidol in rats exposed or not to ketamine, mimicking acute glutamatergic psychosis or naturalistic conditions, respectively. Arc expression was significantly reduced by minocycline compared with controls. Minocycline in combination with haloperidol also significantly reduced Arc expression compared with both controls and haloperidol alone. Moreover, haloperidol/minocycline combination significantly affected Arc expression in cortical regions, while haloperidol alone was ineffective on cortical gene expression. These results suggest that minocycline may strongly affect the expression of Arc as mediated by haloperidol, both in terms of quantitative levels and of topography of haloperidol-related expression. It is noteworthy that no significant pre-treatment effect was found, suggesting that pre-exposure to ketamine did not grossly affect gene expression. Minocycline was not found to significantly affect haloperidol-related Homer1a expression. No significant changes in Homer1b/c expression were observed. These results are consistent with previous observations that minocycline may modulate postsynaptic glutamatergic transmission, affecting distinct downstream pathways initiated by N-methyl-D-aspartate (NMDA) receptor modulation, i.e. Arc-mediated but not Homer1a-mediated pathways.

Background Clozapine is the gold standard for Treatment Resistant Schizophrenia (TRS) and its use is strongly recommended after failure of two/three antipsychotics. Nonetheless, prescribing trends do not appear to follow the global guidelines and switching to clozapine is often delayed or improper. Reasons for clozapine underuse are quite understood, whereas little is known on clozapine misuse. In fact, more stringent operative criteria to define TRS should be used in clinical practice, taking advantage of standardized assessment tools in order to avoid false TRS positive. In these perspectives, we studied the patterns of clozapine prescription in a sample of TRS and non-TRS patients, in order to identify psychopathological variables associated with lifetime exposure to clozapine. Methods 198 consecutive patients have been screened for eligibility criteria from 2016 until 2019 at Treatment Resistant Psychosis Centre of the University of Naples “Federico II”. Only stabilized schizophrenic patients aged between 18 and 65 were enrolled. All relevant clinical-demographic data were recorded. TRS diagnosis was based on TRRIP working group operational criteria and clear pseudo-resistance factors were excluded. Patients were subdivided into two groups: those having received or currently under clozapine treatment (eCLZ) and those never treated by clozapine (nCLZ). Patients were assessed for psychotic symptoms (PANSS), cognitive performances (BACS), neurological soft signs (NES), functional capacity (UPSA), social functioning (PSP and SLOF scales), and severity of illness (CGI-S). Results Among the patients included (92), eCLZ were 50 (54.3%), of which 20% being non-TRS. Compared to nCLZ, eCLZ had a significantly earlier age at onset, more hospitalizations, higher daily antipsychotic doses; eCLZ patients had significantly higher scores on the CGI-S, PANSS total, PANSS Negative, General Psychopathology and PAUSS subscale and, according to the Five Factor PANSS Model, higher score on Negative and Disorganization Factors; eCLZ had also more impaired Working Memory performances, higher NES Total score, lower PSP and all SLOF areas scores, except Area4. Then we use univariate and multivariate analysis to delineate predictors of clozapine exposure and to evaluate whether these factors may organize in proximal (independent) and distal (mediated) associations. We found five independently associated variables that mediate all the other ones: high antipsychotic doses, higher disease severity, suicide attempts, impaired working memory, more severe Stereotyped Thinking. Discussion While it is expected that some TRS patients might not receive clozapine, the observation that non-TRS patients had been exposed to clozapine may surprise. A possible explanation may be the lack of systematized procedure to diagnose TRS, which is often merely coincident with a nonspecific lack of response to antipsychotics. Due to mediation analysis, we further gained insights into the hierarchy of these variables’ impact on clozapine prescription and we finally compose a complex network of proximal and distal factors predicting clozapine exposure in schizophrenic patients. The above-mentioned independent variables significantly associated with clozapine exposure let intend that eCLZ patients may belong to a subset of more severely ill ones, beyond reaching the response threshold. Earlier onset patients may suffer from a more severe disease, be more prone to suicide attempts, and less responsive to antipsychotics. This result needs to be replicated in wider samples, and this relevant therapeutic issue should be further debated in order to gather robust evidence to support or discourage clozapine off-label use and misuse.

This post-hoc study was aimed at assessing whether disease severity was higher in a sample of Treatment Resistant Schizophrenia patients (TRS) compared to schizophrenia patients responsive to antipsychotics (non-TRS). Determinants of disease severity were also investigated in these groups. Eligible patients were screened by standardized diagnostic algorithm to categorize them as TRS or non-TRS. All patients underwent the following assessments: CGI-S; PANSS; DAI; NES; a battery of cognitive tests. Socio-demographic and clinical variables were also recorded. TRS patients exhibited significantly higher disease severity and psychotic symptoms, either as PANSS total score or subscales' scores. A preliminary correlation analysis ruled out clinical and cognitive variables not associated with disease severity in the two groups. Hierarchical linear regression showed that negative symptoms were the clinical variable explaining the highest part of variation in disease severity in TRS, while in non-TRS patients PANSS-General Psychopathology was the variable explaining the highest variation. Mediation analysis showed that negative symptoms mediate the effects of verbal fluency dysfunctions and high-level neurological soft signs (NSS) on TRS' disease severity. These results show that determinants of disease severity sharply differ in TRS and non-TRS patients, and let hypothesize that TRS may stem from cognitive disfunctions and putatively neurodevelopmental aberrations.

Here, we used Receiver Operating Characteristic (ROC) curve analysis to determine whether clinical factors may aid predicting the categorization of schizophrenia patients as Treatment Resistant (TRS) or antipsychotic responsive schizophrenia (ARS). Patients with an established condition of TRS or ARS were assessed for: clinical presentation and course; neurological soft signs (NES); psychopathology by PANSS; cognitive performances; quality of life scale (QLS); functional capacity; social functioning (PSP and SLOF scales). In ROC curve analysis, significance indicated that the Area under curve (AUC) allowed distinguishing between TRS and ARS. Multivariate analyses were additionally used to provide independent predictive analysis. Multiple clinical variables showed significant AUCs. The largest significant AUCs were found for: NES total score; SLOF Area2; QLS subscale; antipsychotic doses. The highest sensitivity was found for NES total score, the highest specificity for previous hospitalizations. The highest Odds Ratio of being included within the TRS category were found for: NES total score (7.5); QLS total score (5.49); and previous hospitalizations (4.76). This same circumscribed group of variables was also found to be predictive of TRS when adopting stepwise logistic regression or discriminant analysis. We concluded that the evaluation of few clinical factors may provide reliable and accurate predictions on whether one schizophrenia patient may be categorized as a TRS.

Caffeine and nicotine are widely used by schizophrenia patients and may worsen psychosis and affect antipsychotic therapies. However, they have also been accounted as augmentation strategies in treatment-resistant schizophrenia. Despite both substances are known to modulate dopamine and glutamate transmission, little is known about the molecular changes induced by these compounds in association to antipsychotics, mostly at the level of the postsynaptic density (PSD), a site of dopamine-glutamate interplay. Here we investigated whether caffeine and nicotine, alone or combined with haloperidol, elicited significant changes in the levels of both transcripts and proteins of the PSD members Homer1 and Arc, which have been implicated in synaptic plasticity, schizophrenia pathophysiology, and antipsychotics molecular action. Homer1a mRNA expression was significantly reduced by caffeine and nicotine, alone or combined with haloperidol, compared to haloperidol. Haloperidol induced significantly higher Arc mRNA levels than both caffeine and caffeine plus haloperidol in the striatum. Arc mRNA expression was significantly higher by nicotine plus haloperidol vs. haloperidol in the cortex, while in striatum gene expression by nicotine was significantly lower than that by both haloperidol and nicotine plus haloperidol. Both Homer1a and Arc protein levels were significantly increased by caffeine, nicotine, and nicotine plus haloperidol. Homer1b mRNA expression was significantly increased by nicotine and nicotine plus haloperidol, while protein levels were unaffected. Locomotor activity was not significantly affected by caffeine, while it was reduced by nicotine. These data indicate that both caffeine and nicotine trigger relevant molecular changes in PSD sites when given in association with haloperidol.

An increasing amount of research aims at recognizing the molecular mechanisms involved in long-lasting brain architectural changes induced by antipsychotic treatments. Although both structural and functional modifications have been identified following acute antipsychotic administration in humans, currently there is scarce knowledge on the enduring consequences of these acute changes. New insights in immediate-early genes (IEGs) modulation following acute or chronic antipsychotic administration may help to fill the gap between primary molecular response and putative long-term changes. Moreover, a critical appraisal of the spatial and temporal patterns of IEGs expression may shed light on the functional "signature" of antipsychotics, such as the propensity to induce motor side effects, the potential neurobiological mechanisms underlying the differences between antipsychotics beyond D2 dopamine receptor affinity, as well as the relevant effects of brain region-specificity in their mechanisms of action. The interest for brain IEGs modulation after antipsychotic treatments has been revitalized by breakthrough findings such as the role of early genes in schizophrenia pathophysiology, the involvement of IEGs in epigenetic mechanisms relevant for cognition, and in neuronal mapping by means of IEGs expression profiling. Here we critically review the evidence on the differential modulation of IEGs by antipsychotics, highlighting the association between IEGs expression and neuroplasticity changes in brain regions impacted by antipsychotics, trying to elucidate the molecular mechanisms underpinning the effects of this class of drugs on psychotic, cognitive and behavioral symptoms.

Antipsychotics may modulate the transcription of multiple gene programs, including those belonging to postsynaptic density (PSD) network, within cortical and subcortical brain regions. Understanding which brain region is activated progressively by increasing doses of antipsychotics and how their different receptor profiles may impact such an activation could be relevant to better correlate the mechanism of action of antipsychotics both with their efficacy and side effects. We analyzed the differential topography of PSD transcripts by incremental doses of two antipsychotics: haloperidol, the prototypical first generation antipsychotic with prevalent dopamine D2 receptors antagonism, and asenapine, a second generation antipsychotic characterized by multiple receptors occupancy. We investigated the expression of PSD genes involved in synaptic plasticity and previously demonstrated to be modulated by antipsychotics: Homer1a, and its related interacting constitutive genes Homer1b/c and PSD95, as well as Arc, C-fos and Zif-268, also known to be induced by antipsychotics administration. We found that increasing acute doses of haloperidol induced immediate-early genes (IEGs) expression in different striatal areas, which were progressively recruited by incremental doses with a dorsal-to-ventral gradient of expression. Conversely, increasing acute asenapine doses progressively de-recruited IEGs expression in cortical areas and increased striatal genes signal intensity. These effects were mirrored by a progressive reduction in locomotor animal activity by haloperidol, and an opposite increase by asenapine. Thus, we demonstrated for the first time that antipsychotics may progressively recruit PSD-related IEGs expression in cortical and subcortical areas when administered at incremental doses and these effects may reflect a fine-tuned dose-dependent modulation of the PSD.

Treatment resistant schizophrenia (TRS) is defined by poor or non-response to conventional antipsychotic agents. Functional capacity is defined as the baseline potential of a patient to function in the community, irrespective of actual achievements gained, and has never been studied in TRS. Here, we screened 182 patients with psychotic symptoms and separated them in TRS (n = 28) and non-TRS (n = 32) ones, to evaluate whether they exhibited differential extents and predictive clinical variables of functional capacity. Functional capacity was measured by the UCSD Performance-Based Skills Assessment (UPSA). Psychotic symptoms by PANSS, social functioning by PSP and SLOF, clinical severity of the illness, cognitive functioning, and neurological soft signs (NSS) were assessed. TRS patients had non-significant lower UPSA scores compared to non-TRS (t-test: p 0.05). In TRS, UPSA score correlated with multiple clinical variables. The highest effect sizes were observed for PANSS negative score (r = -0.67, p 0.005); SLOF Area1 score (r = 0.66, p 0.005); NSS severity (r = -0.61, p 0.005). Multivariate analysis showed that main predictors of UPSA score in TRS patients were PANSS negative score, education years, NSS, Problem Solving performances, and PSP score (F = 11.12, R

Here, we investigated neurological soft signs (NSSs) in treatment resistant schizophrenia (TRS) vs treatment responder schizophrenia (SZ) patients. TRS is a severe condition, affecting approximately one-third of schizophrenia patients and representing a relevant clinical challenge. NSSs are neurological abnormalities reportedly described in schizophrenia patients and linked to dysregulated network connections. We explored the possibility that NSSs may be: i) more severe in TRS patients; ii) differentially associated to clinical/cognitive variables in TRS vs SZ; iii) predictive of having TRS. In addition, we evaluated whether diagnosis may mediate NSSs associations with the above-mentioned variables. Consecutive patients with schizophrenia diagnosis underwent stringent assessment for TRS diagnosis. Demographics and clinical variables were recorded. Psychopathology (by Positive and Negative Syndrome Scale, PANSS), cognitive performances, and NSSs (by Neurological Evaluation Scale, NES) were tested. TRS had higher scores than SZ patients in total NES score and in almost all NES subscales, even after correction for duration of illness and antipsychotic dose (ANCOVA, p

Loxapine is a first generation antipsychotic, belonging to the dibenzoxazepine class. Recently, loxapine has been reformulated at a lower dose, producing an inhaled powder that can be directly administered to the lungs to treat the agitation associated with psychiatric disorders, such as schizophrenia and bipolar disorder. Thus, the aim of this narrative and clinical mini-review was to evaluate the efficacy and tolerability of inhaled loxapine in the treatment of acute agitation in patients with psychiatric disorders. The efficacy of inhaled loxapine has been evaluated in one Phase II trial on patients with schizophrenia, and in two Phase III trials in patients with schizophrenia and bipolar disorder. Moreover, there are two published case series on patients with borderline personality disorder and dual diagnosis patients. Inhaled loxapine has proven to be effective and generally well tolerated when administered to agitated patients with schizophrenia and bipolar disorder. Two case series have suggested that inhaled loxapine may also be useful to treat agitation in patients with borderline personality disorder and with dual diagnosis, but further studies are needed to clarify this point. However, the administration of inhaled loxapine requires at least some kind of patient collaboration, and is not recommended in the treatment of severe agitation in totally uncooperative patients. Moreover, the drug-related risk of bronchospasm must always be kept in mind when planning to use inhaled loxapine, leading to a careful patient assessment prior to, and after, administration. Also, the higher costs of inhaled loxapine, when compared to oral and intramuscular medications, should be taken into account when selecting it for the treatment of agitation.

To summarize risks related to (1) illness and (2) second-generation antipsychotic (SGA) treatment in pregnant women and their offspring. Concerning illness-related risks, we focused on bipolar disorder and schizophrenia, psychiatric disorders for which SGAs are preferentially prescribed. Objective: To summarize risks related to (1) illness and (2) secondgeneration antipsychotic (SGA) treatment in pregnant women and their offspring. Concerning illness-related risks, we focused on bipolar disorder and schizophrenia, psychiatric disorders for which SGAs are preferentially prescribed. Data Sources: PubMed, Ovid, Scopus, PsycINFO, and Cochrane Library were searched from the date of the first available article to October 2015 using the following key terms: pregnancy OR gestation OR bipolar disorder OR schizophrenia. We also included cross-references from identified articles. Study Selection: We included 49 English-language articles regarding illnessrelated and SGA-related risks in bipolar disorder and schizophrenia. First, searches were done for epidemiologic or experimental studies (from January 2000 to October 2015), then for systematic reviews and meta-analyses. Data Extraction: Data were extracted independently, after removing duplicates and studies that were not relevant or not pertinent. Results: Abrupt discontinuation of treatment-exposed mothers with bipolar disorder or schizophrenia led to a high risk of relapses during pregnancy. Both bipolar disorder and schizophrenia were linked to a slightly increased risk of obstetric complications for mothers (schizophrenia) and the newborn (bipolar disorder and schizophrenia), although data on drug exposure during pregnancy were not given in the majority of studies. Maternal morbidity (schizophrenia but not bipolar disorder) may be associated with the worst neonatal outcomes (stillbirth, neonatal or infant deaths, and intellectual disability). Untreated bipolar disorder and schizophrenia may be considered independent risk factors for congenital malformations, while SGAs were not associated with increased recurring defects in fetuses. Evidence regarding the potential effects of SGAs on child neurodevelopment remains reassuring. Conclusion: After taking into account the parents' will and after they provide informed consent, the most reasonable and less harmful choice for treating future mothers with bipolar disorder or schizophrenia appears to be maintaining them at the safest minimum dosage.

Dopamine-glutamate interplay dysfunctions have been suggested as pathophysiological key determinants of major psychotic disorders, above all schizophrenia and mood disorders. For the most part, synaptic interactions between dopamine and glutamate signaling pathways take part in the postsynaptic density, a specialized ultrastructure localized under the membrane of glutamatergic excitatory synapses. Multiple proteins, with the role of adaptors, regulators, effectors, and scaffolds compose the postsynaptic density network. They form structural and functional crossroads where multiple signals, starting at membrane receptors, are received, elaborated, integrated, and routed to appropriate nuclear targets. Moreover, transductional pathways belonging to different receptors may be functionally interconnected through postsynaptic density molecules. Several studies have demonstrated that psychopharmacologic drugs may differentially affect the expression and function of postsynaptic genes and proteins, depending upon the peculiar receptor profile of each compound. Thus, through postsynaptic network modulation, these drugs may induce dopamine-glutamate synaptic remodeling, which is at the basis of their long-term physiologic effects. In this review, we will discuss the role of postsynaptic proteins in dopamine-glutamate signals integration, as well as the peculiar impact of different psychotropic drugs used in clinical practice on postsynaptic remodeling, thereby trying to point out the possible future molecular targets of "synapse-based" psychiatric therapeutic strategies.

INTRODUCTION: Cariprazine (RGH-188) is a novel antipsychotic drug that exerts partial agonism of dopamine D2/D3 receptors with preferential binding to D3 receptor, antagonism of 5HT2B receptors and partial agonism of 5HT1A. Its interesting pharmacodynamic profile suggests its potential in the treatment of a plethora of psychiatric disorders. The present comprehensive review aims at summarizing the current evidence about the safety, tolerability and efficacy of Cariprazine in the treatment of schizophrenia, BD (manic/mixed/depressive episode) and MDD. EVIDENCE ACQUISITION: A literature search was here carried out on PubMed/Medline/Scopus and the database on Clinical Trials from inception until December 2015 by typing a set of specified keywords. EVIDENCE SYNTHESIS: Cariprazine appears to be efficacy in the treatment of cognitive and negative symptoms of schizophrenia. Preliminary findings suggest its antimanic activity whilst it is still under investigation its efficacy in the treatment of bipolar depression and MDD. CONCLUSIONS: Further studies should be needed in order to better identify its clinical efficacy profile.

Background Negative symptoms (NSs) are more severe in Treatment Resistant Schizophrenia (TRS) than Antipsychotic Responder Schizophrenia (ARS) patients. NSs are predictors of outcomes of neurological soft signs and functional capacity in TRS but not in ARS patients. The scope of this work is to clarify whether NSs effects are integral to or independent from the TRS diagnosis in our sample of patients. Methods 70 out of 206 eligible putative TRS and ARS patients were included (enrollment still ongoing). Patients were tested by the Neurological Evaluation Scale (NES); the CGI-S; the PANSS; the Heinrichs’ Quality of Life Scale (QLS); the UCSD Performance-Based Skills Assessment (UPSA); the Personal and Social Performance (PSP) scale and Specific Level of Functioning (SLOF). Patients were subdivided in NSHigh (severe NSs) and NSLow (mild NSs) based on ROC curve-derived cut-off. Results At the Student’s t test, NSHigh had significantly lower scores than NSLow patients on: Verbal Fluency; QLS score; PSP score; UPSA Financial, Communication, and Family Skills; UPSA total score; all SLOF areas (except Area4). NSHigh patients had significantly higher scores than NSLow patients on CGI-S; PANSS Positive and General Psychopathology Subscale scores; and NES score. Distribution of NS patients was significantly different between TRS/ARS diagnostic groups, as NSHigh patients were significantly more frequent in the TRS group (Pearson chi square: □1=5.51, p=.001). Notably, mean PANSS Negative Subscale scores were significantly higher in TRS compared to ARS patients (Student’s t: F1,58=2.84, p=.006). Since multiple variables found to be significantly different in NSHigh vs. NSLow patients were also significantly different between TRS and ARS patients, the question arises whether the significant differences found between diagnostic groups may depend on the higher percentage of patients with more severe NSs in the TRS group. Therefore, a two-way ANOVA was carried out with dichotomous NS and Diagnosis variables as the independent variables. Outcomes on multiple clinical variables were significantly different among groups. A NS*Diagnosis interaction effect was found for NES score (F1,58=4.32, p=.042, Visuospatial Memory, UPSA Transportation skills, and SLOF Area1. In all these cases, NSHigh/TRS patients performed significantly worse than the other patient groups; in the case of NES score, NSHigh/TRS patients score significantly higher than the other groups. Independent effect of either NSs or Diagnosis were also found for multiple variables, suggesting that NSs and Diagnosis may interact but their effects are not completely overlapping. To have a more deepen comprehension of NS effects on diagnosis, we carried out a moderator regression analysis and an ANCOVA analysis that further confirmed the finding that NSs’ mediate Diagnosis effects on a number of clinical outcomes. Given that NSs largely affect clinical variables, we asked which distinct symptom may exert the greater impact on each of these variables. Therefore, we carried out a including the seven PANSS Negative Subscale items as the independent variables. The items that explained the highest variance in clinical variables were mostly Stereotyped Thinking (N7), Passive Social Withdrawal (N4), and Difficulty in Abstract Thinking (N5). Discussion These data suggest that NSs are both independent determinants and moderators of TRS/ARS diagnosis effect on multiple psychopathology, cognitive, and psychosocial factors. More impaired functions attributed to non-response to antipsychotics may depend on more severe NSs. However, only a subset of NSs appears to exert this action, possibly related to the multidimensional construct of these symptoms.

Multiple lines of evidence demonstrate that schizophrenia patients may perform worse than normal controls in several cognitive tasks. However, little is known on putative differences in cognitive functioning between schizophrenia patients responding to antipsychotics and those resistant to the treatment. In this cross-sectional study, 63 subjects (41 schizophrenia and schizoaffective patients and 22 age and sex-matched controls) were enrolled. Patients were divided in resistant (TRS, n=19) and non-resistant to pharmacological treatment (non-TRS, n=22) according to the American Psychiatric Association (APA) criteria for treatment resistance. The Brief Assessment of Cognition in Schizophrenia (BACS) was administered to patients and controls. The following rating scales were administered to schizophrenia patients: the Positive and Negative Syndrome Scale (PANSS), the Drug Attitude Inventory (DAI) and the Subjective Well-being under Neuroleptics (SWN). Statistically significant differences among non-TRS patients, TRS ones, and controls were detected at the BACS. TRS patients performed significantly worse than non-TRS ones on Verbal Memory task, exhibited higher PANSS total and subscales scores and were prescribed higher antipsychotic doses. Poorer performances at the BACS significantly correlated with more severe negative symptoms in TRS but not in non-TRS patients. These results may suggest that TRS patients suffer from a form of the disease with prominent cognitive impairment possibly related to negative symptoms.

Dysfunctions in the interplay among multiple neurotransmitter systems have been implicated in the wide range of behavioral, emotional and cognitive symptoms displayed by major psychiatric disorders, such as schizophrenia, bipolar disorder or major depression. The complex clinical presentation of these pathologies often needs the use of multiple pharmacological treatments, in particular (1) when monotherapy provides insufficient improvement of the core symptoms; (2) when there are concurrent additional symptoms requiring more than one class of medication and (3) in order to improve tolerability, by using two compounds below their individual dose thresholds to limit side effects. To date, the choice of drug combinations is based on empirical paradigm guided by clinical response. Nonetheless, several preclinical studies have demonstrated that drugs commonly used to treat psychiatric disorders may impact common intracellular target molecules (e.g. Akt/GSK-3 pathway, MAP kinases pathway, postsynaptic density proteins). These findings support the hypothesis that convergence at crucial steps of transductional pathways could be responsible for synergistic effects obtained in clinical practice by the co-administration of those apparently heterogeneous pharmacological compounds. Here we review the most recent evidence on the molecular crossroads in antipsychotic combined therapies with antidepressants, mood stabilizers, and benzodiazepines, as well as with antipsychotics. We first discuss clinical clues and efficacy of such combinations. Then we focus on the pharmacodynamics and on the intracellular pathways underpinning the synergistic, or concurrent, effects of each therapeutic add-on strategy, as well as we also critically appraise how pharmacological research may provide new insights on the putative molecular mechanisms underlying major psychiatric disorders.

The present study evaluated consistency, reliability, and determinants of two real-world measures of adherence to prescription in 57 schizophrenia and 61 non-schizophrenia patients. Treatment resistant schizophrenia (TRS) was additionally diagnosed in 28 of the schizophrenia patients. Patients were screened for clinical severity, cognitive functioning, and adherence by 10-item Drug Attitude Inventory (DAI-10) or Adherence-to-Therapy (AtT), a clinician-rated tool developed by our group. DAI-10 and AtT scores showed a significant correlation (p=0.039; ρ=0.21; df=103). Compared to the DAI-10 scale, a higher number of variables were associated with AtT. In schizophrenia and TRS patients, substance abuse was the only significant predictor of lower DAI-10 score (p=0.027, F=5.2, R 2 =0.07, and p=0.06, F=8.9, R 2 =0.23, respectively). Lower AtT score was significantly associated with first-generation antipsychotic use (p=0.001, RR: 2.00 [1.40–2.87]), positive symptoms (p=0.02, RR: 1.63 [1.05–2.53]), impaired verbal fluency (p=0.01, RR: 1.88 [0.81–4.32]) or problem solving (p=0.01, RR: 2.14 [0.92–4.98]). AtT, but not DAI-10, score correlated with the score on the Personal and Social Performance scale (p=0.02, F=5.86, R 2 =0.08). Overall, AtT score was predicted by pharmacological, psychopathological, and cognitive factors, and predictive of psychosocial functioning. Therefore, AtT measure may represent a convenient and practical tool to evaluate schizophrenia patients' adherence.

Cariprazine (RGH-188) is a novel antipsychotic drug that exerts partial agonism of dopamine D2/D3 receptors with preferential binding to D3 receptor, antagonism of 5HT2B receptors and partial agonism of 5HT1A. Currently, cariprazine is in late-stage clinical development (phase III clinical trials) in patients with schizophrenia (S) and in patients with bipolar disorder (BD), as well as an adjunctive treatment in patients with Major Depressive Disorder (MDD) and drug-resistant MDD. Cariprazine has completed phase III trials for the acute treatment of schizophrenia and bipolar mania, phase II trials for the bipolar depression and MDD whilst it is undergoing phase III trials as an adjunct to antidepressants. The present review aims at proving a comprehensive summary of the current evidence on the safety, tolerability and efficacy of cariprazine in the treatment of schizophrenia, BD (manic/mixed/ depressive episode) and MDD. A systematic search was conducted on PubMed/Medline/ Scopus and the database on Clinical Trials from inception until April 2015 by typing a set of specified keywords. Available evidence seems to support cariprazine efficacy in the treatment of cognitive and negative symptoms of schizophrenia. Preliminary findings suggest its antimanic activity whilst it is still under investigation its efficacy in the treatment of bipolar depression and MDD. Furthermore, the available data seems not to allow judgements about its antipsychotic potential in comparison with currently prescribed antipsychotics. Further studies should be carried out to better investigate its pharmacodynamic and clinical potential, particularly as alternative to current antipsychotic drugs.

The aim of this work was to compare achievements in milestones of community functioning in highly disabling psychiatric conditions, including treatment resistant schizophrenia (TRS), schizophrenia (responsive to antipsychotics), bipolar disorder, and anxiety/depressive diseases. Also, we investigated the predictors of community functioning outcomes across several domains. Among consecutive patients screened, 188 met inclusion criteria and 118 ultimately entered the study. Diagnosis of TRS was made by stringent criteria, including historic and perspective evaluations and excluding potential confounding factors. Achievements in functional milestones of everyday living were recorded. Performances in discrete cognitive tasks were assessed. The Positive and Negative Syndrome Scale, the Personal and Social Performance Scale, the Drug Attitude Inventory-10, and the Quality of Life Enjoyment and Satisfaction Questionnaire were administered. TRS patients showed the highest impairment in community functioning among diagnostic groups. TRS was found to have more severe psychopathology, more impaired cognitive functioning, and poorer psychosocial adjustment compared to all the other groups. In the whole sample, the main predictors of community functioning were the diagnostic group (with TRS diagnosis associated with worst functioning) and achievements in the other functional milestones. In psychotic patients, however, the main predictors of community functioning were clinical and psychopathological variables. These results may support the hypothesis that TRS represents a separate schizophrenia subtype, with its own neurobiology, psychopathology and clinical course. Our results identify a group of modifiable predictors to be addressed to prevent community disability.

Synaptic plasticity represents the long lasting activity-related strengthening or weakening of synaptic transmission, whose well-characterized types are the long term potentiation and depression. Despite this classical definition, however, the molecular mechanisms by which synaptic plasticity may occur appear to be extremely complex and various. The post-synaptic density (PSD) of glutamatergic synapses is a major site for synaptic plasticity processes and alterations of PSD members have been recently implicated in neuropsychiatric diseases where an impairment of synaptic plasticity has also been reported. Among PSD members, scaffolding proteins have been demonstrated to bridge surface receptors with their intracellular effectors and to regulate receptors distribution and localization both at surface membranes and within the PSD. This review will focus on the molecular physiology and pathophysiology of synaptic plasticity processes, which are tuned by scaffolding PSD proteins and their close related partners, through the modulation of receptor localization and distribution at post-synaptic sites. We suggest that, by regulating both the compartmentalization of receptors along surface membrane and their degradation as well as by modulating receptor trafficking into the PSD, postsynaptic scaffolding proteins may contribute to form distinct signaling micro-domains, whose efficacy in transmitting synaptic signals depends on the dynamic stability of the scaffold, which in turn is provided by relative amounts and post-translational modifications of scaffolding members. The putative relevance for neuropsychiatric diseases and possible pathophysiological mechanisms are discussed in the last part of this work.

Antipsychotics are the mainstay of schizophrenia treatment. However, approximately one third of schizophrenic patients do not respond or respond poorly to antipsychotics. Therefore, there is a need for new approaches that can improve schizophrenia treatment significantly. Promising strategies arise from the modulation of glutamatergic system, according to its proposed involvement in schizophrenia pathogenesis. In this review, we critically updated preclinical and clinical data on the modulation of glutamate N-methyl-D-aspartate (NMDA) receptor activity by NMDA-Rs co-agonists, glycine transporters inhibitors, AMPAkines, mGluR5 agonists, NMDA-Rs partial agonists. We focused on: 1) preclinical results in animal models mimicking the pathophysiology of psychosis, mainly believed to be responsible of negative and cognitive symptoms, and predicting antipsychotic-like activity of these compounds; and 2) clinical efficacy in open-label and double-blind trials. Albeit promising preclinical findings for virtually all compounds, clinical efficacy has not been confirmed for D-cycloserine. Contrasting evidence has been reported for glycine and D-serine, that may however have a role as add-on agents. More promising results in humans have been found for glycine transporter inhibitors. AMPAkines appear to be beneficial as pro-cognitive agents, while positive allosteric modulators of mGluR5 have not been tested in humans. Memantine has been proposed in early stages of schizophrenia, as it may counteract the effects of glutamate excitotoxicity correlated to high glutamate levels, slowing the progression of negative symptoms associated to more advanced stages of the illness.

IntroductionSchizophrenia is a condition with high impact in terms of disability, also because between 30% and 60% affected individuals do not respond to treatment. It has been proposed that cognitive functioning is strongly impaired in schizophrenia and even more in TRS patients. Cognitive dysfunctions are regarded to worsen psychopathology, psychosocial functioning, and overall course of the illness.ObjectivesTo investigate the impact of Cognitive Remediation (CR) on psychopathology and psychosocial functioning in TRS vs. schizophrenia responder patients.AimsTo determine whether a CR intervention could improve functional outcomes in TRS patients.MethodsWe evaluated proximal and distal effects of CR on approximately 20 schizophrenia responders and 20 TRS patients. Patients in each group were randomized to receive CR or not. Patients were assessed in training task performance, neurocognition, functional capacity, symptoms and psychosocial functioning. Evaluations were conducted at baseline, at the end of the 4-month intervention, and at 6-month, 1 and 2 year-follow-ups. The study is still in active recruitment phase.ResultsBoth TRS and schizophrenia responder patients exposed to CR exhibited a significant improvement in specific neurocognitive domains, and in psychosocial functioning as assessed by either rating scales (SLOF and PSP) and performance-based measures (UPSA) at the 4-month time-point.ConclusionsCR improved psychosocial functioning in both group of patients, however, they were more pronounced in TRS patients.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Agomelatine, a melatonergic antidepressant with a rapid onset of action, is one of the most recent drugs in the antidepressant category. Agomelatine's antidepressant actions are attributed to its sleep-promoting and chronobiotic actions mediated by MT1 and MT2 receptors present in the suprachiasmatic nucleus, as well as to its effects on the blockade of 5-HT2c receptors. Blockade of 5-HT2c receptors causes release of both noradrenaline and dopamine at the fronto-cortical dopaminergic and noradrenergic pathways. The combined actions of agomelatine on MT1/MT2 and 5-HT2c receptors facilitate the resynchronization of altered circadian rhythms and abnormal sleep patterns. Agomelatine appeared to be effective in treating major depression. Moreover, evidence exists that points out a possible efficacy of such drug in the treatment of bipolar depression, anxiety disorders, alcohol dependence, migraines etc. Thus, the aim of this narrative review was to elucidate current evidences on the role of agomelatine in disorders other than major depression.

Despite dopamine-glutamate aberrant interaction that has long been considered a relevant landmark of psychosis pathophysiology, several aspects of these two neurotransmitters reciprocal interaction remain to be defined. The emerging role of postsynaptic density (PSD) proteins at glutamate synapse as a molecular "lego" making a functional hub where different signals converge may add a new piece of information to understand how dopamine-glutamate interaction may work with regard to schizophrenia pathophysiology and treatment. More recently, compelling evidence suggests a relevant role for microRNA (miRNA) as a new class of dopamine and glutamate modulators with regulatory functions in the reciprocal interaction of these two neurotransmitters. Here, we aimed at addressing the following issues: (i) Do miRNAs have a role in schizophrenia pathophysiology in the context of dopamine-glutamate aberrant interaction? (ii) If miRNAs are relevant for dopamine-glutamate interaction, at what level this modulation takes place? (iii) Finally, will this knowledge open the door to innovative diagnostic and therapeutic tools? The biogenesis of miRNAs and their role in synaptic plasticity with relevance to schizophrenia will be considered in the context of dopamine-glutamate interaction, with special focus on miRNA interaction with PSD elements. From this framework, implications both for biomarkers identification and potential innovative interventions will be considered.

A relevant role for dopamine-glutamate interaction has been reported in the pathophysiology and treatment of psychoses. Dopamine and glutamate may interact at multiple levels, including the glutamatergic postsynaptic density (PSD), an electron-dense thickening that has gained recent attention as a switchboard of dopamine-glutamate interactions and for its role in synaptic plasticity. Recently, glutamate-based strategies, such as memantine add-on to antipsychotics, have been proposed for refractory symptoms of schizophrenia, e.g. cognitive impairment. Both antipsychotics and memantine regulate PSD transcripts but sparse information is available on memantine's effects under dopamine perturbation. We tested gene expression changes of the Homer1 and PSD-95 PSD proteins in models of sustained dopamine perturbation, i.e. subchronic treatment by: a) GBR-12909, a dopamine receptor indirect agonist; b) haloperidol, a D2R antagonist; c) SCH-23390, a dopamine D1 receptor (D1R) antagonist; and d) SCH-23390. +. haloperidol. On the last day of treatment, rats were acutely treated with vehicle or memantine. The Homer1a immediate-early gene was significantly induced by haloperidol and by haloperidol. +. SCH-23390. The gene was not induced by SCH-23390 per se or by GBR-12909. Expression of the constitutive genes Homer1b/c and PSD-95 was less affected by these dopaminergic paradigms. Acute memantine administration significantly increased Homer1a expression by the dopaminergic compounds used herein. Both haloperidol and haloperidol. +. SCH-23390 shifted Homer1a/. Homer1b/c ratio of expression toward Homer1a. This pattern was sharpened by acute memantine. Dopaminergic compounds and acute memantine also differentially affected topographic distribution of gene expression and coordinated expression of Homer1a among cortical-subcortical regions. These results indicate that dopaminergic perturbations may affect glutamatergic signaling in different directions. Memantine may help partially revert dopamine-mediated glutamatergic dysfunctions

Felice Iasevoli, Raffaele Balletta, Valentina Gilardi, Sara Giordano, Andrea de Bartolomeis Unit on Treatment Resistance in Psychiatry and Laboratory of Molecular and Translational Psychiatry, Section of Psychiatry, Department of Neuroscience, Reproductive Sciences and Odontostomatology, University School of Medicine ‘Federico II’, Naples, Italy Abstract: Tobacco smoking is common in schizophrenia patients. It has been reported that schizophrenia patients who are tobacco smokers have better cognitive performances compared to those who are nonsmokers. However, little is known on the effects of tobacco smoking in treatment-resistant schizophrenia (TRS) patients. The aim of this study was to compare cognitive performances, psychotic symptoms, and social adjustment in tobacco smoker TRS patients compared to nonsmoker TRS patients. Smoker and nonsmoker TRS patients did not differ in demographics and in mean daily antipsychotic dose. Smoker TRS patients had significantly higher scores than nonsmoker patients on the positive and negative syndrome scale (PANSS) and on the negative symptoms subscale. These patients also performed worse than nonsmoker patients on problem-solving cognitive domain. Social adjustment was not significantly different between the two groups. In both groups of patients, worse cognitive performances were mostly predicted by higher severity of negative symptoms. Worse performances on the verbal memory and problem-solving cognitive domains were correlated with social-functioning impairment in tobacco smoker TRS patients but not in nonsmoker ones. The results showed that tobacco smoking was not significantly associated with better cognitive performances in TRS patients, while it was significantly associated with higher negative symptoms. Even if a direct causative mechanism cannot be inferred and despite the fact that these patients may use tobacco to self-medicate, it could be speculated that these associations may, at least partially, be related to a tobacco-smoking–induced worsening of abnormal dopamine dysfunction, which has been suggested to occur in TRS patients. Keywords: dopamine, nicotine, psychosis, antipsychotic, cortex, refractory

Emerging researches point to a relevant role of postsynaptic density (PSD) proteins, such as PSD-95, Homer, Shank, and DISC-1, in the pathophysiology of schizophrenia and autism spectrum disorders. The PSD is a thickness, detectable at electronic microscopy, localized at the postsynaptic membrane of glutamatergic synapses, and made by scaffolding proteins, receptors, and effector proteins; it is considered a structural and functional crossroad where multiple neurotransmitter systems converge, including the dopaminergic, serotonergic, and glutamatergic ones, which are all implicated in the pathophysiology of psychosis. Decreased PSD-95 protein levels have been reported in postmortem brains of schizophrenia patients. Variants of Homer1, a key PSD protein for glutamate signaling, have been associated with schizophrenia symptoms severity and therapeutic response. Mutations in Shank gene have been recognized in autism spectrum disorder patients, as well as reported to be associated to behaviors reminiscent of schizophrenia symptoms when expressed in genetically engineered mice. Here, we provide a critical appraisal of PSD proteins role in the pathophysiology of schizophrenia and autism spectrum disorders. Then, we discuss how antipsychotics may affect PSD proteins in brain regions relevant to psychosis pathophysiology, possibly by controlling synaptic plasticity and dendritic spine rearrangements through the modulation of glutamate-related targets. We finally provide a framework that may explain how PSD proteins might be useful candidates to develop new therapeutic approaches for schizophrenia and related disorders in which there is a need for new biological treatments, especially against some symptom domains, such as negative symptoms, that are poorly affected by current antipsychotics.

Oxytocin is a nonapeptide mammalian hormone, best known for its role in childbirth, parturition and lactation. It has been implicated in the control of social behaviors and relationships, such as monogamy or promiscuous behaviors. The putative involvement of oxytocin in schizophrenia was first postulated following several pioneer reports of oxytocin use in schizophrenia and observations of increased oxytocin levels in the cerebrospinal fluid of schizophrenic patients, although this latter finding has subsequently been challenged. More recently, oxytocin plasma levels have been found to be decreased in schizophrenic individuals, particularly in those exhibiting hyponatremic polydipsia and emotional dysregulation. Some authors report that intranasal oxytocin administration to schizophrenic patients may reduce symptomatology. The aim of the present paper was to review studies investigating symptomatology, social cognition and emotion recognition changes in DSM-IV-TR schizophrenic patients, after administration of intranasal oxytocin at different doses. Literature search was conducted in March, 2012. PubMed and Scopus databases were used to find studies for inclusion in the systematic review. Oxytocin may represent an important novel adjunctive treatment for patients with schizophrenia. However, some limitations of current studies cannot be overlooked and further investigations are certainly needed.

IntroductionCariprazine (RGH-188) is a novel antipsychotic drug that exerts partial agonism of dopamine D2/D3 receptors with preferential binding to D3 receptor, antagonism of 5HT2B receptors and partial agonism of 5HT1A. Currently, cariprazine is in late-stage clinical development (phase III clinical trials) in patients with schizophrenia (S) and in patients with bipolar disorder (BD), as well as an adjunctive treatment in patients with Major Depressive Disorder (MDD) and drug-resistant MDD.ObjectivesCariprazine has completed phase III trials for the acute treatment of schizophrenia and bipolar mania, phase II trials for the bipolar depression and MDD whilst it is undergoing phase III trials as an adjunct to antidepressants.AimsThe present review aims at proving a comprehensive summary of the current evidence on the safety, tolerability and efficacy of cariprazine in the treatment of schizophrenia, BD (manic/mixed/depressive episode) and MDD.MethodsA systematic search was conducted on PubMed/Medline/Scopus and the database on Clinical Trials from inception until April 2015 by typing a set of specified keywords.ResultsAvailable evidence seems to support cariprazine efficacy in the treatment of cognitive and negative symptoms of schizophrenia. Preliminary findings suggest its antimanic activity whilst it is still under investigation its efficacy in the treatment of bipolar depression and MDD. Furthermore, the available data seems not to allow judgements about its antipsychotic potential in comparison with currently prescribed antipsychotics.ConclusionsFurther studies should be carried out to better investigate its pharmacodynamic and clinical potential, particularly as alternative to current antipsychotic drugs.Disclosure of interestThe authors have not supplied their declaration of competing interest.