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Introduction: The effects of antipsychotic drugs are dose-dependent, which is particularly true for their efficacy, each antipsychotic having a specific dose-response curve. This may justify individualizing doses for these agents. Areas covered: We review the pharmacokinetic profiles of seven oral antipsychotics: haloperidol, risperidone, olanzapine, clozapine, quetiapine, ziprasidone, and aripiprazole. Their main indications are psychotic and affective disorders. They are prescribed in a very large population which may have comorbidities. Hence, we analyze the impact of the latter on the pharmacokinetic profiles of these antipsychotics, focusing on renal and hepatic impairment. Reviews and clinical trials were discussed based on a systematic literature search (PubMed) ranging from 1995 to 2022. Expert opinion: Factors liable to impact antipsychotic dosage are numerous and their subsequent effects often hard to predict, due to multilevel interactions and compensatory phenomena. In clinical practice, physicians must be aware of these potential effects, but base their decisions on monitoring antipsychotic plasma levels.

The inherent risk of agranulocytosis associated with clozapine requires the realization of weekly white blood cell monitoring (WBCM) during the 18 first weeks of treatment. The aim of this study was to assess the compliance with WBCM during clozapine initiation for schizophrenia and Parkinson's disease (PD) subjects.The analysis was conducted using SNDS data on a cohort of new users of clozapine in 2018. We analyzed all reimbursements for WBCM from 2 weeks before the index date to 18 weeks after (optimal monitoring during hospitalization was assumed). The primary outcome was the proportion of good realization of WBCM according to different thresholds of completion (70%; 80%; 90%). Descriptive and comparative analyses with chi-squared test or Student's t-test were performed.Two hundred and ninety-six subjects were included. Rates of patients with WBCM realization over 70%, 80%, and 90% of WBCM expected were, respectively, 78.1%, 70.0%, and 56.9% for subjects with schizophrenia and 71.3%, 63.2%, and 47.8% for PD subjects. Only hospitalization during the follow-up period for schizophrenia subjects was significantly associated with good WBCM realization.We observed rather good results for compliance with clozapine initial monitoring. Other studies are needed to confirm our results.

A single non-anaesthetic dose of ketamine, a non-competitive NMDA receptor (NMDAr) antagonist with hallucinogenic properties, induces cognitive impairment and psychosis, and aggravates schizophrenia symptoms in patients. In conscious rats an equivalent dose of ketamine induces key features of animal models of acute psychosis, including abnormal behaviour, hyperlocomotion, deficits in prepulse inhibition to an acoustic startle response and gating of auditory evoked potentials, and concomitantly increases the power of spontaneously occurring gamma oscillations in the neocortex. This study investigated whether NMDAr antagonist-induced aberrant gamma oscillations could be modulated by acute treatment with typical and atypical antipsychotic drugs. Adult male Wistar rats that has been implanted with extradural electrodes were placed in an arena for 30 minutes (baseline) and then subcutaneously administered either clozapine (1–5mg/kg, n=7), haloperidol (0.05 – 0.25mg/kg; n=8), LY379268 (a preclinical agonist at mGluR2/3 receptors: 0.3 – 3mg/kg; n=5) or their vehicles alone, and 30 minutes later received ketamine (5mg/kg sc). Quantitative measures of EEG gamma power and locomotor activity were assessed throughout the experiment. All three drugs significantly reduced the power of baseline EEG gamma oscillations by 30–50%, an effect most prominent after LY379268, and all inhibited ketamine-induced hyperlocomotor activity. However, only pretreatment with LY379268 attenuated trough-to-peak ketamine-induced gamma hyperactivity. These results demonstrate that typical and atypical antipsychotic drugs acutely reduce cortical gamma oscillations, an effect that may be related to their clinical efficacy.

Schizophrenia is a common mental illness, causing a strong stigma sometimes linked to aggressive risk conveyed by the media. Although this risk is only slightly increased compared to the general population, some patients may have hetero-aggressive behavior and they must be supported. No treatment has been developed to specifically address this aggressive behavior, but a few studies on our current therapies begin to show interest. Despite this, our practice usually consists in the administration of a first-generation antipsychotic, with the idea that they would be more effective against the aggressiveness of this patients, mainly related to an increase in sedative effect. However, second-generation antipsychotics, neurologically better tolerated and enabling better compliance, could make a treatment of choice in the prevention of aggressiveness from this schizophrenic patients. It is for this purpose that we conducted a literature review of current knowledge about effectiveness of first- and second-generation antipsychotics on this type of behavior. With this knowledge, we then conducted a cross-sectional study from the Buss Perry Aggression Questionnaire, measuring aggressiveness of 331 schizophrenic patients of Expert Center, depending on the received antipsychotic type. The analysis of these two studies allows us to attempt giving treatment recommendations for use with the most violent schizophrenic patients.; La schizophrénie est une maladie mentale fréquente, sujette à une forte stigmatisation de la part des média, parfois en lien avec le risque agressif associé. Bien que ce risque ne soit que peu majoré par rapport à la population générale, certains patients peuvent présenter des passages à l’acte hétéro-agressifs et ceux-ci doivent être pris en charge. Aucun traitement n’a été développé spécifiquement vis-à-vis de cette dimension, mais quelques études portant sur nos thérapeutiques actuelles commencent à s’y intéresser. Malgré cela, notre pratique consiste généralement en l’administration d’un antipsychotique de première génération, dans l’idée qu’il serait plus efficace envers l’agressivité de nos patients, principalement en lien avec une augmentation de la sédation. Cependant, le développement des antipsychotiques de seconde génération, mieux tolérés sur le plan neurologique et permettant une meilleure observance, pourrait en faire un traitement de choix dans la prévention des passages à l’acte agressifs des patients schizophrènes. C’est dans ce but que nous avons réalisé une revue de la littérature, afin de faire le point sur les connaissances actuelles autour de l’efficacité des antipsychotiques de première et de seconde génération sur ce type de comportement. Fort de ces connaissances, nous avons ensuite mené une étude transversale, à partir de la Buss Perry Aggression Questionnaire, mesurant l’agressivité chez 331 patients schizophrènes reçus dans les Centres Experts, en fonction du type d’antipsychotique reçu. L’analyse de ces deux travaux nous a permis de suggérer des recommandations thérapeutiques utilisables auprès des patients schizophrènes les plus violents.

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International audience; Exposure to psychostimulants and antipsychotics increases neurotensin (NT) gene expression in the striatum and nucleus accumbens. To investigate the contribution of D(3) receptors to these effects we used mice with targeted disruption of the D(3) receptor gene. Basal NT mRNA expression was similar in D(3) receptor mutant mice and wild-type animals. Acute administration of haloperidol increased NT gene expression in the striatum in D(3)+/+, D(3)+/- and D(3)-/- mice. Similarly, acute cocaine and amphetamine induced NT mRNA expression in the nucleus accumbens shell and olfactory tubercle to a comparable extent in D(3) mutants and wild-type mice. Daily injection of cocaine for seven days increased NT mRNA in a restricted population of neurons in the dorsomedial caudal striatum of D(3)+/+ mice, but not in D(3)-/- and D(3)+/- animals. No differences were observed between D(3) receptor mutant mice and wild-type littermates in the locomotor activity and stereotyped behaviors induced by repeated cocaine administration. These findings demonstrate that dopamine D(3) receptors are not necessary for the acute NT mRNA response to drugs of abuse and antipsychotics but appear to play a role in the regulation of NT gene induction in striatal neurons after repeated cocaine. In addition, our results indicate that the acute locomotor response to cocaine and development of psychostimulant-induced behavioral sensitization do not require functional D(3) receptors.

Most physiological effects of σ 1 receptor ligands are sensitive to pertussis toxin, suggesting a coupling with cell membrane-bound G proteins. However, the cloning of the σ 1 receptor has allowed the identification of an intracellular protein anchored on the endoplasmic reticulum. Here, we show, using the isolated adult guinea pig brainstem preparation, that activation of the σ 1 receptor results in its translocation from the cytosol to the vicinity of the cell membrane and induces a robust and rapid decrease in hypoglossal activity, which is mediated by phospholipase C. The subsequent activation of protein kinase C β 1 and β 2 isoforms and the phosphorylation of a protein of the same molecular weight as the cloned σ 1 receptor lead to a desensitization of the σ 1 motor response. Our results indicate that the intracellular σ 1 receptor regulates several components implicated in plasma membrane-bound signal transduction. This might be an example of a mechanism by which an intracellular receptor modulates metabotropic responses.

International audience; OBJECTIVE: We report preliminary results from use of a radioreceptor assay (RRA) to measure serum haloperidol levels and their relation to clinical response and adverse effects in 19 psychotic patients with positive symptoms treated with haloperidol. METHODS: Blood samples were taken on Days 7, 14 and 21. Clinical evaluation was based on the PANSS, and UKU scales. The D2 antidopaminergic RRA was used to measure haloperidol serum levels. RESULTS: Our results show a correlation between psychosis with positive symptoms assessed by positive scores in the PANSS and the serum drug level measured by RRA concentrations. The observed relationship made it possible to establish a therapeutic serum range of haloperidol equivalents 15-30 ng/ml-1. This range contained no "non-responders". Analysis of the correlation between each item on the positive subscale of the PANSS and the RRA concentration suggested that there was no specific symptom of psychosis closely related to RRA concentration during the first 15 days of treatment. In the third week, however, certain specific symptoms were closely connected to the RRA concentration. CONCLUSION: From these results, it can be concluded that antipsychotic activity can be related to blockade of serum D2 dopamine receptors. In future would be desirable to monitor neuroleptic treatment in this way. The study also showed that the antipsychotic treatment did not correct any specific component of the psychosis during the first stage of the treatment but that it did so at later times.

International audience; The purpose of this study was to identify clinician characteristics associated with higher prescription rates of long-acting injectable (LAI) antipsychotics, as well as the sources that influence medical decision-making regarding the treatment of schizophrenia. We surveyed 202 psychiatrists during six regional French conferences (Bordeaux, Lyon, Marseille, Nice, Paris, and Strasbourg). Data on the characteristics of practice, prescription rates of antipsychotic, and information sources about their clinical decisions were collected. Most psychiatrists used second-generation antipsychotics (SGAs), and preferentially an oral formulation, in the treatment of schizophrenia. LAI SGAs were prescribed to 30.4% of schizophrenic patients. The duration and type of practice did not influence the class or formulation of antipsychotics used. The clinicians following the higher percentage of schizophrenic patients were associated with a higher use of LAI antipsychotics and a lower use of oral SGAs. Personal experience, government regulatory approval, and guidelines for the treatment of schizophrenia were the three main contributing factors guiding clinicians' decision-making regarding the treatment of schizophrenia. The more clinicians follow schizophrenic patients, the more they use LAI antipsychotics. The development of specialized programs with top specialists should lead to better use of LAI antipsychotics in the treatment of schizophrenia.

International audience; This study aimed to develop a joint population pharmacokinetic model for an antipsychotic agent in development (S33138) and its active metabolite (S35424) produced by reversible metabolism. Because such a model leads to identifiability problems and numerical difficulties, the model building was performed using the FOCE-I and the Stochastic Approximation Expectation Maximization (SAEM) estimation algorithms in NONMEM and MONOLIX, respectively. Four different structural models were compared based on Bayesian information criteria. Models were first written as ordinary differential equations systems and then in closed form (CF) to facilitate further analyses. The impact of polymorphisms on genes coding for the CYP2C19 and CYP2D6 enzymes, respectively involved in the parent drug and the metabolite elimination were investigated using permutation Wald test. The parent drug and metabolite plasma concentrations of 101 patients were analyzed on two occasions after 4 and 8 weeks of treatment at 1, 3, 6, and 24 h following daily oral administration. All configurations led to a two compartment model with back-transformation of the metabolite into the parent drug and a first-pass effect. The elimination clearance of the metabolite through other processes than back-transformation was decreased by 35% [9-53%] in CYP2D6 poor metabolizer. Permutation tests were performed to ensure the robustness of the analysis, using SAEM and CF. In conclusion, we developed a complex joint pharmacokinetic model adequately predicting the impact of CYP2D6 polymorphisms on the parent drug and its metabolite concentrations through the back-transformation mechanism.

International audience; This study aimed to develop a joint population pharmacokinetic model for an antipsychotic agent in development (S33138) and its active metabolite (S35424) produced by reversible metabolism. Because such a model leads to identifiability problems and numerical difficulties, the model building was performed using the FOCE-I and the Stochastic Approximation Expectation Maximization (SAEM) estimation algorithms in NONMEM and MONOLIX, respectively. Four different structural models were compared based on Bayesian information criteria. Models were first written as ordinary differential equations systems and then in closed form (CF) to facilitate further analyses. The impact of polymorphisms on genes coding for the CYP2C19 and CYP2D6 enzymes, respectively involved in the parent drug and the metabolite elimination were investigated using permutation Wald test. The parent drug and metabolite plasma concentrations of 101 patients were analyzed on two occasions after 4 and 8 weeks of treatment at 1, 3, 6, and 24 h following daily oral administration. All configurations led to a two compartment model with back-transformation of the metabolite into the parent drug and a first-pass effect. The elimination clearance of the metabolite through other processes than back-transformation was decreased by 35% [9-53%] in CYP2D6 poor metabolizer. Permutation tests were performed to ensure the robustness of the analysis, using SAEM and CF. In conclusion, we developed a complex joint pharmacokinetic model adequately predicting the impact of CYP2D6 polymorphisms on the parent drug and its metabolite concentrations through the back-transformation mechanism.

International audience; This study aimed to develop a joint population pharmacokinetic model for an antipsychotic agent in development (S33138) and its active metabolite (S35424) produced by reversible metabolism. Because such a model leads to identifiability problems and numerical difficulties, the model building was performed using the FOCE-I and the Stochastic Approximation Expectation Maximization (SAEM) estimation algorithms in NONMEM and MONOLIX, respectively. Four different structural models were compared based on Bayesian information criteria. Models were first written as ordinary differential equations systems and then in closed form (CF) to facilitate further analyses. The impact of polymorphisms on genes coding for the CYP2C19 and CYP2D6 enzymes, respectively involved in the parent drug and the metabolite elimination were investigated using permutation Wald test. The parent drug and metabolite plasma concentrations of 101 patients were analyzed on two occasions after 4 and 8 weeks of treatment at 1, 3, 6, and 24 h following daily oral administration. All configurations led to a two compartment model with back-transformation of the metabolite into the parent drug and a first-pass effect. The elimination clearance of the metabolite through other processes than back-transformation was decreased by 35% [9-53%] in CYP2D6 poor metabolizer. Permutation tests were performed to ensure the robustness of the analysis, using SAEM and CF. In conclusion, we developed a complex joint pharmacokinetic model adequately predicting the impact of CYP2D6 polymorphisms on the parent drug and its metabolite concentrations through the back-transformation mechanism.

Recent studies have suggested that schizophrenia is associated with alterations in the synaptic connectivity involving cytoskeletal proteins. The microtubule-associated protein STOP (Stable Tubule Only Polypeptide) plays a key-role in neuronal architecture and synaptic plasticity and it has been demonstrated that STOP gene deletion in mice leads to a phenotype mimicking aspects of positive and negative symptoms and cognitive deficits classically observed in schizophrenic patients. In STOP-null mice, behavioral defects are associated with synaptic plasticity abnormalities including defects in long-term potentiation. In these mice, long-term administration of typical antipsychotics has been shown to partially alleviate behavioral defects but, as in humans, such a treatment was poorly active on deficits related to negative symptoms and cognitive impairments. Here, we assessed the effects of risperidone and clozapine, two atypical antipsychotics, on STOP-null mice behavior and synaptic plasticity. Long-term administration of either drug results in alleviation of behavioral alterations mimicking some negative symptoms and partial amelioration of some cognitive defects in STOP-null mice. Interestingly, clozapine treatment also improves synaptic plasticity of the STOP- null animals by restoring long-term potentiation in the hippocampus. All together, the pharmacological reactivity of STOP-null mice to antipsychotics evokes the pharmacological response of humans to such drugs. Totally, our study suggests that STOP-null mice may provide a useful preclinical model to evaluate pharmacological properties of antipsychotic drugs.

International audience; Schizophrenia is a common psychiatric illness (1% of the general population), characterized by the association of positive and negative symptoms and cognitive disorders. Antipsychotics, typical or atypical, are known to induce in patients with schizophrenia weight gain and abnormalities in glucose and lipid metabolisms. These modifications, in addition to metabolic risk factors, intrinsic to the psychiatric illness (physical inactivity, smoking, diabetes), increase the risk of cardiovascular complications. Some antipsychotics are associated with a higher risk of metabolic disorders. Before starting such a medication, all risk factors must be taken into account. In case of even effectiveness, one should consider the risk of inducing metabolic disorders, as well as the intrinsic risk factors of the patient, in order to prescribe the medication associated with the lower metabolic risk. Regarding iatrogenic diabetes, the risk of occurrence seems different, depending on the molecules, being more marked for clozapine, olanzapine, risperidone, quietapine then amisulpride, aripiprazole and finally ziprasidone. The physiopathology seems to involve both an increase in insulin resistance and an alteration of insulin secretion. Nevertheless, the benefit/risk often remains largely in favour of treatment, the atypical antipsychotics are at least equally effective and better tolerated on the cognitive and neurological functions than conventional antipsychotics being. They have particularly far fewer extrapyramidal effects. The reversibility of pathologies induced by atypical antipsychotics led to the formulation of guidelines, leading to regular clinical and biological follow-up.

International audience; Recently evidence has accumulated that schizophrenia can arise from primary synaptic defects involving structural proteins particularly, microtubule associated proteins. Previous experiments have demonstrated that a STOP (stable tubule only peptide) gene deletion in mice leads to a phenotype mimicking some aspects of positive symptoms classically observed in schizophrenic patients. In the current study, we determined if STOP null mice demonstrate behavioral abnormalities related to the social and cognitive impairments of schizophrenia. Compared with wild-type mice, STOP null mice exhibited deficits in the non-aggressive component of social recognition, short term working memory and social and spatial learning. As described in humans, learning deficits in STOP null mice were poorly sensitive to long term treatment with typical neuroleptics. Since social and cognitive dysfunction have consistently been considered as central features of schizophrenia, we propose that STOP null mice may provide a useful model to understand the neurobiological correlates of social and cognitive defects in schizophrenia and to develop treatments that better target these symptoms.

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International audience; Cohort studies suggest that exposure to antipsychotic agents may be associated with an increased risk of venous thromboembolism (VTE). Few data concerning antidepressant drugs are available. Using a different methodological approach, the aim of this study was to estimate the association between neuroleptic and antidepressant drug use and the risk of VTE. We report the results of a case-control study designed to evaluate interactions between acquired and inherited risk factors of VTE. We included 677 cases hospitalized with deep vein thrombosis and or pulmonary embolism with no major acquired risk factor for VTE, and 677 controls matched for gender and age. Drug exposure was defined as current use of drugs at admission. Neuroleptic exposure was associated with an increased risk of VTE (OR = 2.1, 95% CI 1.4-3.2). Among neuroleptics, antipsychotic agent use was associated with a 3.5-fold increased risk of VTE (OR = 3.5, 95% CI 2.0-6.2). No association was found between antidepressant drug exposure and the risk of VTE (OR = 1.1, 95% CI 0.9-1.5). In this hospital-based case-control study, exposure to antipsychotic drugs was associated with an increased risk of VTE. These results, added to previous results, suggest that clinicians should consider antipsychotic drug exposure as a potential risk factor of VTE. More studies are needed in order to further elucidate this adverse effect, and to determine the possible predisposing factors and the biological mechanisms involved.

Schizophrenia is a chronic mental illness affecting 0.4% of the population. Existing antipsychotic drugs are mainly used to treat positive symptoms such as hallucinations but have only poor effects on negative symptoms such as cognitive deficits or depression. TREK and TRAAK channels are two P domain background potassium channels activated by polyunsaturated fatty acids and mechanical stress. TREK but not TRAAK channels are regulated by Gs- and Gq-coupled pathways. The inactivation of the TREK-1 but not the TRAAK channel in mice results in a depression-resistant phenotype. In addition, it has been shown that antidepressants such as fluoxetine or paroxetine directly inhibit TREK channel activity. Here we show that different antipsychotic drugs directly inhibit TREK currents with IC(50) values of approximately 1 to approximately 20 microM. No effect is seen on TRAAK channel activity. We conclude that TREK channels might be involved in the therapeutic action of antipsychotics or in their secondary effects. Furthermore, TREK channels could play a role in the pathophysiology of psychiatric disorders such as depression and schizophrenia.

International audience; BACKGROUND: Second-generation antipsychotic drugs were introduced over a decade ago for the treatment of schizophrenia; however, their purported clinical effectiveness compared with first-generation antipsychotic drugs is still debated. We aimed to compare the effectiveness of second-generation antipsychotic drugs with that of a low dose of haloperidol, in first-episode schizophrenia. METHODS: We did an open randomised controlled trial of haloperidol versus second-generation antipsychotic drugs in 50 sites, in 14 countries. Eligible patients were aged 18-40 years, and met diagnostic criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder. 498 patients were randomly assigned by a web-based online system to haloperidol (1-4 mg per day; n=103), amisulpride (200-800 mg per day; n=104), olanzapine (5-20 mg per day; n=105), quetiapine (200-750 mg per day; n=104), or ziprasidone (40-160 mg per day; n=82); follow-up was at 1 year. The primary outcome measure was all-cause treatment discontinuation. Patients and their treating physicians were not blinded to the assigned treatment. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN68736636. FINDINGS: The number of patients who discontinued treatment for any cause within 12 months was 63 (Kaplan-Meier estimate 72%) for haloperidol, 32 (40%) for amisulpride, 30 (33%) for olanzapine, 51 (53%) for quetiapine, and 31 (45%) for ziprasidone. Comparisons with haloperidol showed lower risks for any-cause discontinuation with amisulpride (hazard ratio [HR] 0.37, [95% CI 0.24-0.57]), olanzapine (HR 0.28 [0.18-0.43]), quetiapine (HR 0.52 [0.35-0.76]), and ziprasidone (HR 0.51 [0.32-0.81]). However, symptom reductions were virtually the same in all the groups, at around 60%. INTERPRETATION: This pragmatic trial suggests that clinically meaningful antipsychotic treatment of first-episode of schizophrenia is achievable, for at least 1 year. However, we cannot conclude that second-generation drugs are more efficacious than is haloperidol, since discontinuation rates are not necessarily consistent with symptomatic improvement.

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To establish the impact of antipsychotic medication on the incidence of diabetes, we have analysed data from the prospective French Cohort study of mortality in schizophrenia. This generated a large database of 3470 patients with schizophrenia initially enrolled in 1993 for which data collection on comorbidity has been collected systematically every three years since. The primary objective of the study was to evaluate the mortality rate in the study cohort. From this database, the prevalence and incidence of diabetes can be studied. In 1993, nine patients in 10 were prescribed conventional antipsychotics and the remainder amisulpride and clozapine. Since the introduction of risperidone and olanzapine, atypical antipsychotics are now used in one-third of patients. Multiple antipsychotic medications are used in many patients, with the exception of those receiving clozapine. At inclusion, 2.2% of patients in the study cohort had a diagnosis of diabetes. Morbidity rates were higher in females than in males (3.4% and 1.6%, respectively) and it was only in females that the standard morbidity ratio with respect to the general population was significantly elevated (2.2; 95% confidence intervals: 1.6 and 2.9). The prevalence of diabetes in the study cohort rose over the course of the study. Multivariate regression analysis was performed in order to identify potential determinants of diabetes. For pre-existing diabetes, four factors were identified: age at first hospitalisation, age, obesity and duration of schizophrenia. The same factors with the exception of length of illness were identified for the incident cases. There was no evidence for an interaction between the class and type of antipsychotic medication and risk of treatment emergent diabetes. However, the use of multiple antipsychotic treatments makes the individualisation of specific risks associated with any other antipsychotic drug impossible.

International audience; Neuroleptics are thought to exert their anti-psychotic effects by counteracting a hyper-dopaminergic transmission. Here, we have examined the dopaminergic status of STOP (stable tubule only polypeptide) null mice, which lack a microtubule-stabilizing protein and which display neuroleptic-sensitive behavioural disorders. Dopamine transmission was investigated using both behavioural analysis and measurements of dopamine efflux in different conditions. Compared to wild-type mice in basal conditions or following mild stress, STOP null mice showed a hyper-locomotor activity, which was erased by neuroleptic treatment, and an increased locomotor reactivity to amphetamine. Such a behavioural profile is indicative of an increased dopaminergic transmission. In STOP null mice, the basal dopamine concentrations, measured by quantitative microdialysis, were normal in both the nucleus accumbens and the striatum. When measured by electrochemical techniques, the dopamine efflux evoked by electrical stimulations mimicking physiological stimuli was dramatically increased in the nucleus accumbens of STOP null mice, apparently due to an increased dopamine release, whereas dopaminergic uptake and auto-inhibition mechanisms were normal. In contrast, dopamine effluxes were slightly diminished in the striatum. Together with previous results, the present study indicates the association in STOP null mice of hippocampal hypo-glutamatergy and of limbic hyper-dopaminergy. Such neurotransmission defects are thought to be central to mental diseases such as schizophrenia.

International audience; Schizophrenia is a chronic and debilitating disease which is thought to arise from a neuro-developmental disorder. Both the stable tubule-only polypeptide (STOP) protein and the N-methyl-D-aspartate (NMDA) NR1 subunit are involved in neuronal development and physiology. It has therefore been postulated that transgenic mice lacking either the STOP or the NMDAR1 gene would show a 'schizophrenic-like' phenotype. Here, STOP knockout and NMDA NR1 hypomorphic mice were assessed in a behavioural measure that can be used to detect schizophrenic-like phenotypes: a change in sensorimotor gating, measured through prepulse inhibition (PPI). STOP knockout mice were further assessed in another measure of 'schizophrenic-like behaviour': hyperlocomotion. The PPI deficit exhibited by both the STOP knockout and NMDA knockdown mice could not be reversed by acute treatment with the atyptical antipsychotic, clozapine (1 mg/kg, i.p.) but the hyperlocomotion shown by the STOP knockout mice was reversed with the same acute dose of clozapine.

International audience; Depression is a frequent symptom in psychiatry, either isolated (major depression) or entangled with other psychiatric symptoms (psychotic depression, depression of bipolar disorders). Many antidepressant drugs are available with different pharmacological profiles from different classes: tricyclic antidepressants, monoamine oxydase inhibitors, selective serotonin reuptake inhibitors (SSRI). However, there are some limitations with these drugs because there is a long delay before relief for symptoms, some patients with major depression are resistant to treatment, there is a risk to induce manic symptoms in patients with bipolar disorders and these drugs have no effect on the psychotic symptoms frequently associated to major depression. The leading hypothesis for the search of more efficient new antidepressants has been the amine deficit hypothesis: noradrenaline and/or serotonin deficit and more recently dopamine deficit. Moreover, a dopamine deficit has been also hypothesized as the central mechanism explaining the negative symptoms of schizophrenia. These symptoms are the consequence of a deficit of normal behaviours and include affective flattening, alogia, apathy, avolition and social withdrawal. There is thus a great overlap between symptoms of depression and negative symptoms of schizophrenia. Atypical antipsychotics, in contrast with conventional neuroleptics, have been shown to decrease negative symptoms, most probably through the release of dopamine in prefrontal cortex, thus improving psychomotor activity, motivation, pleasure, appetite, etc. The dopamine deficit in cortical prefrontal areas was thus an unifying hypothesis to explain both some symptoms of depression and negative symptoms of schizophrenia. Studies in animal confirm this view and show that the association of an atypical antipsychotic drug and an SSRI (olanzapine plus fluoxetine) increases synergistically the release of dopamine in prefrontal areas. Moreover, most of the atypical antipsychotics have a large action spectrum, beyond the only dopamine receptors: their effects on the serotonin receptors--particularly the 5-HT2A and 5-HT2C receptors--suggest that their association to SSRI could be a promising treatment for depression. Indeed, SSRI act mainly by increasing the serotonin level in the synapse, thus leading to a non specific activation of all pre- and post-synaptic serotonin receptors. Among them, 5-HT2A/2C receptors have been involved in some of the unwanted effects of SSRI: agitation, anxiety, insomnia, sexual disorders, etc. The inhibition of these receptors could be thus beneficial for patients treated with SSRI. Amisulpride is an unique atypical antipsychotic that selectively blocks dopamine receptors presynaptically in the frontal cortex, possibly enhancing dopaminergic transmission. The antidepressant effect of amisulpride was shown in dysthymia in many clinical studies versus placebo, tricyclic antidepressants, SSRI or others. However, a shorter delay for symptom relief was not demonstrated for amisulpride as compared to comparative antidepressants. Other atypical antipsychotics (clozapine, olanzapine), which act on a large variety of receptors, have shown antidepressant effects--mainly in association with SSRI--in different psychiatric diseases: treatment-resistant major depression, major depression with psychotic symptoms and depression of bipolar disorders, with no increase of manic symptoms in this latter case. Moreover, the delay for symptom relief was greatly shortened. More comparative double-blind studies are required to confirm and to precise the antidepressant effects of atypical antipsychotics. Nevertheless, these studies suggest that atypical anti-psychotics could be of great value in depressive conditions reputed for their resistance to treatment with usual antidepressants. Particularly, new strategies emerge that combine atypical antipsychotics and antidepressants for greater efficacy and more rapid relief of depression symptoms.

International audience; When treating patients with manic states, the physician has to deal with at least two main Issues. First, the therapeutic decision has to be rapid because of the unpredictability of its immediate course. This concerns often results in polypharmacy with adjunct treatments. However, the therapeutic choice has to be cautious since part of the treatment will be maintained for prophylaxis. According to recent guidelines, the use of monotherapy with mood stabilisers during acute manic states concerns only few patients with mostly hypomania to moderate mania. Up to date, antipsychotics and benzodiazepines are considered as adjunct treatment in mania with psychotic symptoms or hostility. However, survey studies show that antipsychotics are widely used as adjunct treatments to mood stabilisers, indeed beyond the indications held by the guidelines. Our objective was to describe the clinical situations justifying the addition of an adjunct treatment during acute mania and to clear up from published data, the advantages and the inconveniences of combining antipsychotics and/or benzodiazepines with a mood stabilisers in order to define differentiated indications. Mania associated with either agitation, sleep disturbances or psychotic symptoms requires most of the time to combine mood stabiliser and respectively, sedative and/or anxiolytic, hypnotic or anti-psychotic treatments. Patients suffering from mania associated with other disorders need specific treatment adjustment and combination related to their medical condition. Adjunctive conventional antipsychotic remains widely used in first intention treatment. The conventional antipsychotic is often prescribed alone in the first weeks prior to the association with a mood stabiliser. Nevertheless there are controversies in the literature about their efficiency and their delay of action with regard to other treatments. When the conventional antipsychotic is a part of their initial treatment, manic patients remain taking them when discharged from hospital and are still taking them after 6 Months in a great percentage of the cases. The adverse events with conventional antipsychotic are numerous and severe enough in bipolar patients to restrict their use in first intention mainly to psychotic mania. Moreover, there are evidences for higher sensitivity to adverse effects of the conventional antipsychotics in manic patients. When agitation in acute mania requires an adjunct to mood stabiliser, the conventional antipsychotic treatment could be use for over-excitation without catatonic features and with particular care with the risk of akathisia. Long term effects of conventional antipsychotics, especially on depressive recurrences, should argue to stop them as soon as possible. Since the safety of adjunctive new antipsychotics with mood stabilisers seems until now acceptable, its indication should be limited to acute psychotic manias. Adjunctive benzodiazepine, should be evaluated in the various types of mania with specific concerns with comorbidity frequently met in consultation-liaison psychiatry. Benzodiazepines plus mood stabilisers may be the treatment of choice for the manias in which anxious state, catatonic symptoms or sleeplessness.

International audience; The aim of the study was to examine the action of low-dose amisulpride (100 mg/d), an atypical antipsychotic from the benzamide class with a high affinity for the D2 and D3 dopamine receptors, given for 4 weeks in 19 schizophrenic patients with the deficit syndrome, in terms of clinical response, modifications in their cognitive performance and changes in brain perfusion values. A secondary objective was to distinguish between primary and secondary deficit, according to Carpenter's definition. Both efficacy and a relatively low rate of side effects of low-dose amisulpride in the deficit forms of schizophrenia were found as expected from earlier placebo-controlled studies. Our study found significant changes in the cerebral blood flow, before and after treatment, more marked in the frontal area and particularly in the dorso-lateral frontal area. A significant improvement of cognitive function was found after treatment, without a link to any particular changes in a loco-regional perfusion value. Finally, a distinction between primary and secondary deficit showed a higher percentage of clinical improvement in the patients with a secondary deficit. The psychometric and cerebral perfusion changes were no different in the two groups.

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International audience; Exposure to psychostimulants and antipsychotics increases neurotensin (NT) gene expression in the striatum and nucleus accumbens. To investigate the contribution of D(3) receptors to these effects we used mice with targeted disruption of the D(3) receptor gene. Basal NT mRNA expression was similar in D(3) receptor mutant mice and wild-type animals. Acute administration of haloperidol increased NT gene expression in the striatum in D(3)+/+, D(3)+/- and D(3)-/- mice. Similarly, acute cocaine and amphetamine induced NT mRNA expression in the nucleus accumbens shell and olfactory tubercle to a comparable extent in D(3) mutants and wild-type mice. Daily injection of cocaine for seven days increased NT mRNA in a restricted population of neurons in the dorsomedial caudal striatum of D(3)+/+ mice, but not in D(3)-/- and D(3)+/- animals. No differences were observed between D(3) receptor mutant mice and wild-type littermates in the locomotor activity and stereotyped behaviors induced by repeated cocaine administration. These findings demonstrate that dopamine D(3) receptors are not necessary for the acute NT mRNA response to drugs of abuse and antipsychotics but appear to play a role in the regulation of NT gene induction in striatal neurons after repeated cocaine. In addition, our results indicate that the acute locomotor response to cocaine and development of psychostimulant-induced behavioral sensitization do not require functional D(3) receptors.

International audience; Clozapine and olanzapine behave as weak H3-receptor antagonists in vitro with Ki values around 1 and 50 microM, respectively. Despite these modest apparent affinities, both compounds given orally to mice, nearly doubled steady-state tele-methylhistamine levels in brain, with ED50 values as low as 1 and 3 mg/kg, respectively, an effect comparable to those of potent H3-receptor antagonists. This effect corresponded to an enhancement of histamine turnover rate from 45 to 73 ng/g/h as measured in the case of olanzapine using the pargyline test. Other antipsychotics displaying, such as clozapine and olanzapine, high 5-hydroxytryptamine (5-HT)2A receptor antagonist potency, i.e., risperidone, thioridazine, seroquel, and iloperidone, also enhanced markedly tele-methylhistamine levels. This effect was 1) additive with that of a pure H3-receptor antagonist, ciproxifan, 2) mimicked by a 5-HT2A receptor antagonist, ketanserin, 3) reversed by a 5-HT2A receptor agonist, DOI, 4) not shared by antipsychotics with low affinity for the 5-HT2A receptor, i.e., haloperidol, sulpiride, raclopride, or remoxipride that, on the contrary, tended to reduce tele-methylhistamine levels. We conclude that in contrast to "typical" antipsychotics, "atypical" antipsychotics stimulate histamine neuron activity via blockade of the 5-HT2A receptor in vivo. This effect does not appear to account for their reduced extrapyramidal side-effects but may underlie their pro-cognitive properties.

International audience; Neuroleptics are the main biological treatment for psychotic patients. The brutal withdrawal of a neuroleptic treatment may induce an important aggravation of the psychotic symptoms. A few of those relapses may occur very early after the interruption of treatment; they are often associated with a modification of the symptoms and an unfavorable evolution in the course of the illness. Using those clinical observations a few authors have developed the concept of supersensitivity psychosis to explain those kinds of relapses and to formulate hypothesis about tolerance and resistance to neuroleptics. They focus on the possible correlation between supersensitivity psychosis and tardive dyskinesia. We report three cases of a dramatic aggravation of the psychotic symptomatology following the withdrawal of clozapine in three schizophrenic patients resistant to classical neuroleptic treatment. According to the clinical data and to the physiopathological hypothesis, the concept of supersensitivity psychosis can have implications in the therapeutic management of resistant schizophrenic patients.

International audience; The effect of cyamemazine a dopamine D2 receptor antagonist on voluntary ethanol consumption in rats and on ethanol withdrawal in mice was examined. Male Sprague-Dawley rats were tested in a free choice (water and 10% ethanol) experiment and consumed 5 g/kg ethanol daily. Rats were treated daily IP with cyamemazine (0.5, 1, or 2 mg/kg) or acamprosate (100 mg/kg) during 2 weeks. Both acamprosate and 1 mg/kg cyamemazine significantly decreased ethanol intake by 45% without affecting either fluid or food intake. The lowest dose of cyamemazine had no effect on alcohol intake but increased food intake. The highest dose had no effect on any variables. During the post-treatment period, only 1 mg/kg cyamemazine decreased both ethanol and fluid intakes. Mice were made dependent on alcohol using a chocolate fluid diet containing increasing concentrations of alcohol and withdrawn after 9 days. Mice were treated with cyamemazine (1 or 0.5 mg/kg, respectively) or with the same doses of lorazepam acutely on the day of withdrawal or chronically (during alcohol treatment). Both chronic and acute cyamemazine and lorazepam treatments decreased convulsions during ethanol withdrawal. Both acute treatments decreased locomotor activity in control and alcohol dependent mice. Chronic treatment had no effect on locomotor activity. We suggest that cyamemazine could reduce alcohol consumption by antagonizing the activation of the dopaminergic pathways during the induction of alcohol dependence. The action of cyamemazine on 5-HT3 receptors could also explain its effect on alcohol convulsions during withdrawal convulsions.

International audience; BACKGROUND: Neuroleptic malignant syndrome (NMS) is a potentially lethal adverse effect to neuroleptic drugs. METHODS: We report on 2 cases where NMS dramatically improved with carbamazepine. Incidental removal and reapplication of carbamazepine attests to its effectiveness for this condition. RESULTS: A 34-year-old woman treated for a major depressive disorder experienced NMS with a phenothiazine. Her condition dramatically improved in 8 hours after she was administered carbamazepine. Since carbamazepine was discontinued, NMS recurred in 10 hours and remitted anew within less than 24 hours after reintroduction. A 31-year-old woman experiencing a schizoaffective disorder displayed NMS with aphenothiazine and a butyrophenone. NMS completely resolved within 8 hours after she was administered carbamazepine. NMS recurred within 12 hours after carbamazepine discontinuation. CONCLUSIONS: These data thus account for a cause-effect relationship between carbamazepine administration and NMS relief, and argue against the neuroleptic withdrawal to be responsible by itself for NMS relief.

International audience; Dysregulation of free radical metabolism has been supposed to be involved in schizophrenia etiopathogeny. Recently, Wang et al. showed a red blood cell super oxide dismutase increase in positive schizophrenia (Crow's type I), but neither in negative schizophrenia (Crow's type II) nor in controls. The study included 28 in-patients suffering from acute positive psychosis who were compared with 15 controls. We confirmed the results of Wang. We found a significantly red blood cell Super oxide dismutase increase in positive psychosis, in comparison to negative psychosis and controls (p = 0.0001). This SOD increase was in relationship with the degree of clinical psychomotor excitement. After 21 days of neuroleptic treatment, SOD activity decreased and reached standard values. These results support the hypothesis of striking relationships between catecholaminergic hyper-metabolism and SOD increase, in positive psychosis. These could account for psychotic positive symptoms improvement with neuroleptic treatment, which blocks dopamine pathways.