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Impulsive and compulsive problem behaviours are associated with a variety of mental disorders. Latent phenotyping indicates the expression of impulsive and compulsive problem behaviours is predominantly governed by a transdiagnostic 'disinhibition' phenotype. In a cohort of 117 individuals, recruited as part of the Neuroscience in Psychiatry Network (NSPN), we examined how brain functional connectome and network properties relate to disinhibition. Reduced functional connectivity within a subnetwork of frontal (especially right inferior frontal gyrus), occipital and parietal regions was linked to disinhibition. Findings provide insights into neurobiological pathways underlying the emergence of impulsive and compulsive disorders. [ABSTRACT FROM AUTHOR]

BackgroundLithium and quetiapine are considered standard maintenance agents for bipolar disorder yet it is unclear how their efficacy compares with each other.AimsTo investigate the differential effect of lithium and quetiapine on symptoms of depression, mania, general functioning, global illness severity and quality of life in patients with recently stabilised first-episode mania.MethodMaintenance trial of patients with first-episode mania stabilised on a combination of lithium and quetiapine, subsequently randomised to lithium or quetiapine monotherapy (up to 800 mg/day) and followed up for 1 year. (Trial registration: Australian and New Zealand Clinical Trials Registry - ACTRN12607000639426.)ResultsIn total, 61 individuals were randomised. Within mixed-model repeated measures analyses, significant omnibus treatment × visit interactions were observed for measures of overall psychopathology, psychotic symptoms and functioning. Planned and post hoc comparisons further demonstrated the superiority of lithium treatment over quetiapine.ConclusionsIn people with first-episode mania treated with a combination of lithium and quetiapine, continuation treatment with lithium rather than quetiapine is superior in terms of mean levels of symptoms during a 1-year evolution. [ABSTRACT FROM AUTHOR]

Background: The anterior cingulate cortex is frequently implicated in the pathophysiology of bipolar disorder, but magnetic resonance imaging (MRI) studies have reported variable findings owing to a reliance on patient samples with chronic illness and to limited appreciation of the region's heterogeneity.Aims: To characterise anterior cingulate cortex abnormalities in patients with bipolar disorder experiencing their first episode of psychosis while accounting for regional anatomical variability.Method: Grey matter volume, surface area and cortical thickness were measured in six anterior cingulate cortex subregions per hemisphere using MRI scans acquired from 26 patients with bipolar I disorder experiencing first-episode psychosis and 26 healthy controls matched for age, gender and regional morphological variability.Results: Relative to controls, male patients displayed increased thickness in the right subcallosal limbic anterior cingulate cortex. No significant differences were identified in females for grey matter volume or surface area measures. The findings were not attributable to medication effects.Conclusions: These data suggest that first-episode psychosis in bipolar disorder is associated with a gender-specific, right-lateralised thickness increase in anterior cingulate cortex subregions known to play a role in regulating physiological stress responses. [ABSTRACT FROM AUTHOR]

Background: The anterior cingulate cortex (ACC) is consistently implicated in the pathophysiology of schizophrenia, and our own work has identified morphological anomalies in the ACC of people with this disorder.Aims: To examine whether ACC morphological anomalies are present in a group at ultra-high risk of psychosis and whether such anomalies can be used to predict the subsequent development of a psychotic illness.Method: Magnetic resonance imaging of 75 healthy volunteers and 63 people at ultra-high risk of developing a psychotic disorder (all right-handed males) was used to examine ACC sulcal and gyral features.Results: Compared with the controls, significantly fewer people in the ultra-high risk group had a well-developed left paracingulate sulcus and significantly more had an interrupted left cingulate sulcus. There was no difference between those who did (n=21) and did not (n=42) subsequently develop a psychotic illness.Conclusions: Although ACC anomalies are present in young people considered to be at ultra-high risk of psychosis, they do not identify individuals who subsequently make the transition to psychosis. [ABSTRACT FROM AUTHOR]

Background: The aetiological boundary between obsessive-compulsive related disorders (OCRDs) including obsessive-compulsive disorder (OCD) and anxiety disorders is unclear and continues to generate debate.Aims: To determine the genetic overlap and the pattern of causal relationships among OCRDs and anxiety disorders.Method: Multivariate twin modelling methods and a new regression analysis to infer causation were used, involving 2495 male and female twins.Results: The amount of common genetic liability observed for OCD symptoms was higher when considering anxiety disorders and OCRDs in the model v. modelling OCRD symptoms alone. OCD symptoms emerged as risk factors for the presence of generalised anxiety, panic and hoarding symptoms, whereas social phobia appeared as a risk factor for OCD symptoms.Conclusions: OCD represents a complex phenotype that includes important shared features with anxiety disorders and OCRDs. The novel patterns of risk identified between OCD and anxiety disorder may help to explain their frequent co-occurrence. [ABSTRACT FROM AUTHOR]

BackgroundAlthough severe hoarding symptoms have been considered rare among obsessive-compulsive disorder (OCD) samples, the prevalence of animal hoarding in OCD is unknown. To help clarifying this issue, we searched for cases of animal hoarding among patients attending a university OCD clinic (n=420).MethodsChart review.ResultsOnly two patients from our sample exhibited animal hoarding (<0.5%) and only one of them presented additional obsessive-compulsive symptoms. Both cases also collected inanimate objects, presented low insight, exhibited poor response to serotonin reuptake inhibitors and did not adhere to therapy.ConclusionsThere seems to be a lack of relationship between animal hoarding and OCD. However, further studies with larger numbers of patients are needed to better define their psychopathological profile and more appropriate nosological insertion. [ABSTRACT FROM AUTHOR]

Investigating etiological processes early in the life span represents an important step toward a better understanding of the development of personality pathology. The current study evaluated the interaction between an individual difference risk factor (i.e., temperament) and a biological risk factor for aggressive behavior (i.e., atypical [larger] rightward hippocampal asymmetry) in predicting the emergence of borderline personality disorder (BPD) and antisocial personality disorder symptoms during early adolescence. The sample consisted of 153 healthy adolescents (M = 12.6 years, SD -- 0.4, range = 11.4-13.7) who were selected from a larger sample to maximize variation in temperament. Interactions between four temperament factors (effortful control, negative affectivity, surgency, and affiliativeness), based on the Early Adolescent Temperament Questionnaire--Revised, and volumetric measures of hippocampal asymmetry were examined as cross-sectional predictors of BPD and antisocial personality disorder symptoms. Boys were more likely to have elevated BPD symptoms if they were high on affiliation and had larger rightward hippocampal asymmetry. In boys, low affiliation was a significant predictor of BPD symptoms in the presence of low rightward hippocampal asymmetry. For girls, low effortful control was associated with elevated BPD symptoms in the presence of atypical rightward hippocampal asymmetry. This study builds on previous work reporting significant associations between atypical hippocampal asymmetry and poor behavioral regulation. [ABSTRACT FROM AUTHOR]

It has been suggested that biological factors confer increased sensitivity to environmental influences on depressive symptoms during adolescence, a crucial time for the onset of depressive disorders. Given the critical role of the hippocampus in sensitivity to stress and processing of contextual aspects of the environment, investigation of its role in determining sensitivity to environmental context seems warranted. This study prospectively examined hippocampal volume as a measure of sensitivity to the influence of aggressive maternal behavior on change in depressive symptoms from early to midadolescence. The interaction between aggressive maternal behavior and hippocampal volume was found to predict change in depressive symptoms. Significant sex differences also emerged, whereby only for girls were larger bilateral hippocampal volumes more sensitive to the effects of maternal aggressive behavior, particularly with respect to experiencing the protective effects of low levels of maternal aggressiveness. These findings help elucidate the complex relationships between brain structure, environmental factors such as maternal parenting style, and sensitivity to (i.e., risk for, and protection from) the emergence of depression during this life stage. Given that family context risk factors are modifiable, our findings suggest the potential utility of targeted parenting interventions for the prevention and treatment of adolescent depressive disorder. [ABSTRACT FROM AUTHOR]

Background: Previous studies on substance-dependent populations have shown that age of first use and duration of use are associated with alterations in regional brain volumes. However, it is not clear whether such alterations are factors that predispose young people to use, and so are also present in recreational users, or are a consequence of chronic exposure to substances and/or comorbid psychopathology. Objective: To investigate relationships between key brain structures and parameters of alcohol and cannabis use, in otherwise healthy male recreational users. Method: High-resolution magnetic resonance imaging was used to measure hippocampal, amygdala, whole-brain and intracranial cavity (ICC) volumes in 22 young men with a history of both alcohol and cannabis use. Results: Linear regression analyses with hippocampal, amygdala and whole-brain volumes as the dependent variables and age and ICC as covariates were performed. Findings showed that use of cannabis and alcohol at an earlier age were independently predictive of larger amygdala volumes, whereas longer duration of cannabis use was predictive of smaller hippocampal volumes. Conclusions: Our findings offer preliminary support for a relationship between patterns of substance use and regional brain volumes in recreational users. It is speculative, but possible that this relationship is an evidence of a neurobiological vulnerability to drug-taking behaviour. [ABSTRACT FROM AUTHOR]

Objective: To illustrate the need to carefully consider mental health, psychosocial and motivational factors when investigating cognitive and intellectual impairment among chronic inhalant users. Methods: Two adolescent chronic inhalant users with similar psychosocial disadvantages (eg unstable and dysfunctional families, state-based care, school absenteeism and forensic issues) and histories of comorbid drug use and mental health problems were assessed using a battery of paper and pencil and computerised neuropsychological tests. Results: Contrary to the expectations of her case manager, one participant performed within the normal range for her age in all domains of intellectual ability, while the other participant, in line with the expectations of her case manger, showed marked cognitive deficits and intellectual disability. Conclusions: The typically complex presentation of chronic inhalant users (ie disadvantaged psychosocial backgrounds, comorbid psychopathology and poor motivation/engagement) is rarely considered when investigating associated cognitive and intellectual functioning. Future research should more carefully consider the role of such factors, given the evidence suggesting that they can considerably alter (accentuate or diminish) the association between inhalant abuse and neuropsychological impairment. [ABSTRACT FROM AUTHOR]

Background: Both impulsivity and compulsivity have been identified as risk factors for problematic use of the internet (PUI). Yet little is known about the relationship between impulsivity, compulsivity and individual PUI symptoms, limiting a more precise understanding of mechanisms underlying PUI., Aims: The current study is the first to use network analysis to (a) examine the unique association among impulsivity, compulsivity and PUI symptoms, and (b) identify the most influential drivers in relation to the PUI symptom community., Method: We estimated a Gaussian graphical model consisting of five facets of impulsivity, compulsivity and individual PUI symptoms among 370 Australian adults (51.1% female, mean age = 29.8, s.d. = 11.1). Network structure and bridge expected influence were examined to elucidate differential associations among impulsivity, compulsivity and PUI symptoms, as well as identify influential nodes bridging impulsivity, compulsivity and PUI symptoms., Results: Results revealed that four facets of impulsivity (i.e. negative urgency, positive urgency, lack of premeditation and lack of perseverance) and compulsivity were related to different PUI symptoms. Further, compulsivity and negative urgency were the most influential nodes in relation to the PUI symptom community due to their highest bridge expected influence., Conclusions: The current findings delineate distinct relationships across impulsivity, compulsivity and PUI, which offer insights into potential mechanistic pathways and targets for future interventions in this space. To realise this potential, future studies are needed to replicate the identified network structure in different populations and determine the directionality of the relationships among impulsivity, compulsivity and PUI symptoms.

Objective: "Subsyndromal" obsessive-compulsive disorder symptoms (OCDSs) are common and cause impaired psychosocial functioning. OCDSs are better captured by dimensional models of psychopathology, as opposed to categorical diagnoses. However, such dimensional approaches require a deep understanding of the underlying neurocognitive drivers and impulsive and compulsive traits (ie, neurocognitive phenotypes) across symptoms. This study investigated inhibitory control and self-monitoring across impulsivity, compulsivity, and their interaction in individuals (n = 40) experiencing mild-moderate OCDSs., Methods: EEG recording concurrent with the stop-signal task was used to elicit event-related potentials (ERPs) indexing inhibitory control (ie, N2 and P3) and self-monitoring (ie, error-related negativity and correct-related negativity (CRN): negativity following erroneous or correct responses, respectively)., Results: During unsuccessful stopping, individuals high in both impulsivity and compulsivity displayed enhanced N2 amplitude, indicative of conflict between the urge to respond and need to stop ( F (3, 33) = 1.48, P < .05, 95% Cl [-0.01, 0.001]). Individuals high in compulsivity and low in impulsivity showed reduced P3 amplitude, consistent with impairments in monitoring failed inhibitory control ( F (3, 24) = 2.033, P < .05, 95% CI [-0.002, 0.045]). Following successful stopping, high compulsivity (independent of impulsivity) was associated with lower CRN amplitude, reflecting hypo-monitoring of correct responses ( F (4, 32) = 4.76, P < .05, 95% CI [0.01, 0.02]), and with greater OCDS severity ( F (3, 36) = 3.32, P < .05, 95% CI [0.03, 0.19])., Conclusion: The current findings provide evidence for differential, ERP-indexed inhibitory control and self-monitoring profiles across impulsive and compulsive phenotypes in OCDSs.

Background: Poor mental health is a state of psychological distress that is influenced by lifestyle factors such as sleep, diet, and physical activity. Compulsivity is a transdiagnostic phenotype cutting across a range of mental illnesses including obsessive-compulsive disorder, substance-related and addictive disorders, and is also influenced by lifestyle. Yet, how lifestyle relates to compulsivity is presently unknown, but important to understand to gain insights into individual differences in mental health. We assessed (a) the relationships between compulsivity and diet quality, sleep quality, and physical activity, and (b) whether psychological distress statistically contributes to these relationships., Methods: We collected harmonized data on compulsivity, psychological distress, and lifestyle from two independent samples (Australian n = 880 and US n = 829). We used mediation analyses to investigate bidirectional relationships between compulsivity and lifestyle factors, and the role of psychological distress., Results: Higher compulsivity was significantly related to poorer diet and sleep. Psychological distress statistically mediated the relationship between poorer sleep quality and higher compulsivity, and partially statistically mediated the relationship between poorer diet and higher compulsivity., Conclusions: Lifestyle interventions in compulsivity may target psychological distress in the first instance, followed by sleep and diet quality. As psychological distress links aspects of lifestyle and compulsivity, focusing on mitigating and managing distress may offer a useful therapeutic approach to improve physical and mental health. Future research may focus on the specific sleep and diet patterns which may alter compulsivity over time to inform lifestyle targets for prevention and treatment of functionally impairing compulsive behaviors.

Objective: To (1) confirm whether the Habit, Reward, and Fear Scale is able to generate a 3-factor solution in a population of obsessive-compulsive disorder and alcohol use disorder (AUD) patients; (2) compare these clinical groups in their habit, reward, and fear motivations; and (3) investigate whether homogenous subgroups can be identified to resolve heterogeneity within and across disorders based on the motivations driving ritualistic and drinking behaviors., Methods: One hundred and thirty-four obsessive-compulsive disorder (n = 76) or AUD (n = 58) patients were assessed with a battery of scales including the Habit, Reward, and Fear Scale, the Yale-Brown Obsessive-Compulsive Scale, the Alcohol Dependence Scale, the Behavioral Inhibition/Activation System Scale, and the Urgency, (lack of ) Premeditation, (lack of ) Perseverance, Sensation Seeking, and Positive Urgency Impulsive Behavior Scale., Results: A 3-factor solution reflecting habit, reward, and fear subscores explained 56.6% of the total variance of the Habit, Reward, and Fear Scale. Although the habit and fear subscores were significantly higher in obsessive-compulsive disorder (OCD) and the reward subscores were significantly greater in AUD patients, a cluster analysis identified that the 3 clusters were each characterized by differing proportions of OCD and AUD patients., Conclusions: While affective (reward- and fear-driven) and nonaffective (habitual) motivations for repetitive behaviors seem dissociable from each other, it is possible to identify subgroups in a transdiagnostic manner based on motivations that do not match perfectly motivations that usually described in OCD and AUD patients.

Impulsive and compulsive problem behaviours are associated with a variety of mental disorders. Latent phenotyping indicates the expression of impulsive and compulsive problem behaviours is predominantly governed by a transdiagnostic 'disinhibition' phenotype. In a cohort of 117 individuals, recruited as part of the Neuroscience in Psychiatry Network (NSPN), we examined how brain functional connectome and network properties relate to disinhibition. Reduced functional connectivity within a subnetwork of frontal (especially right inferior frontal gyrus), occipital and parietal regions was linked to disinhibition. Findings provide insights into neurobiological pathways underlying the emergence of impulsive and compulsive disorders.

Background: The extent to which obsessive-compulsive and related disorders (OCRDs) are impulsive, compulsive, or both requires further investigation. We investigated the existence of different clusters in an online nonclinical sample and in which groups DSM-5 OCRDs and other related psychopathological symptoms are best placed., Methods: Seven hundred and seventy-four adult participants completed online questionnaires including the Cambridge-Chicago Compulsivity Trait Scale (CHI-T), the Barratt Impulsiveness Scale (BIS-15), and a series of DSM-5 OCRDs symptom severity and other psychopathological measures. We used K-means cluster analysis using CHI-T and BIS responses to test three and four factor solutions. Next, we investigated whether different OCRDs symptoms predicted cluster membership using a multinomial regression model., Results: The best solution identified one "healthy" and three "clinical" clusters (ie, one predominantly "compulsive" group, one predominantly "impulsive" group, and one "mixed"-"compulsive and impulsive group"). A multinomial regression model found obsessive-compulsive, body dysmorphic, and schizotypal symptoms to be associated with the "mixed" and the "compulsive" clusters, and hoarding and emotional symptoms to be related, on a trend level, to the "impulsive" cluster. Additional analysis showed cognitive-perceptual schizotypal symptoms to be associated with the "mixed" but not the "compulsive" group., Conclusions: Our findings suggest that obsessive-compulsive disorder; body dysmorphic disorder and schizotypal symptoms can be mapped across the "compulsive" and "mixed" clusters of the compulsive-impulsive spectrum. Although there was a trend toward hoarding being associated with the "impulsive" group, trichotillomania, and skin picking disorder symptoms did not clearly fit to the demarcated clusters.

Background: Compulsivity can be seen across various mental health conditions and refers to a tendency toward repetitive habitual acts that are persistent and functionally impairing. Compulsivity involves dysfunctional reward-related circuitry and is thought to be significantly heritable. Despite this, its measurement from a transdiagnostic perspective has received only scant research attention. Here we examine both the psychometric properties of a recently developed compulsivity scale, as well as its relationship with compulsive symptoms, familial risk, and reward-related attentional capture., Methods: Two-hundred and sixty individuals participated in the study (mean age = 36.0 [SD = 10.8] years; 60.0% male) and completed the Cambridge-Chicago Compulsivity Trait Scale (CHI-T), along with measures of psychiatric symptoms and family history thereof. Participants also completed a task designed to measure reward-related attentional capture (n = 177)., Results: CHI-T total scores had a normal distribution and acceptable Cronbach's alpha (0.84). CHI-T total scores correlated significantly and positively (all p < 0.05, Bonferroni corrected) with Problematic Usage of the Internet, disordered gambling, obsessive-compulsive symptoms, alcohol misuse, and disordered eating. The scale was correlated significantly with history of addiction and obsessive-compulsive related disorders in first-degree relatives of participants and greater reward-related attentional capture., Conclusions: These findings suggest that the CHI-T is suitable for use in online studies and constitutes a transdiagnostic marker for a range of compulsive symptoms, their familial loading, and related cognitive markers. Future work should more extensively investigate the scale in normative and clinical cohorts, and the role of value-modulated attentional capture across compulsive disorders.

Background: Although problematic pornography use (PPU) will soon be diagnosable through the International Classification for Diseases, 11th revision, its clinical profile remains contentious. The current study assessed whether PPU may be characterized by various symptoms sometimes observed among online recovery forums that currently lack empirical assessment, such as heightened cognitive-affective issues following pornography use and sexual dysfunction with partners as a result of escalating use., Method: Cross-sectional surveys were completed by male PPUs (N = 138, mean age = 31.75 years, standard deviation = 10.72) recruited via online recovery communities and Amazon Mechanical Turk. Multiple regression analysis was performed using the Problematic Pornography Use Scale as the dependent variable and variables of interest (Arizona Sexual Experiences Scales modified for partnered sex and pornography use, Brunel Mood Scale, Social Interaction Anxiety Scale, and the Tolerance subscale from the Problematic Pornography Consumption Scale) and potential confounders (eg, comorbid psychopathology) as independent variables., Results: Current levels of pornography use, indicators of tolerance and escalation, greater sexual functioning with pornography, and psychological distress were uniquely associated with PPU severity, while cognitive-affective issues after pornography use, impulsivity and compulsivity were not. Although sexual dysfunction did not predict PPU severity, nearly half the sample indicated sexual dysfunction with intimate partners., Conclusions: The present findings suggest that PPU may be characterized by tolerance and escalation (as per substance addiction models), greater sexual responsivity toward pornography, and psychological distress. Meanwhile, the high rate of partnered sexual dysfunction observed suggests that PPU might be somewhat separable from other forms of compulsive sexual behavior.

Objective: We assessed self-reported drives for alcohol use and their impact on clinical features of alcohol use disorder (AUD) patients. Our prediction was that, in contrast to "affectively" (reward or fear) driven drinking, "habitual" drinking would be associated with worse clinical features in relation to alcohol use and higher occurrence of associated psychiatric symptoms., Methods: Fifty-eight Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) alcohol abuse patients were assessed with a comprehensive battery of reward- and fear-based behavioral tendencies. An 18-item self-report instrument (the Habit, Reward and Fear Scale; HRFS) was employed to quantify affective (fear or reward) and non-affective (habitual) motivations for alcohol use. To characterize clinical and demographic measures associated with habit, reward, and fear, we conducted a partial least squares analysis., Results: Habitual alcohol use was significantly associated with the severity of alcohol dependence reflected across a range of domains and with lower number of detoxifications across multiple settings. In contrast, reward-driven alcohol use was associated with a single domain of alcohol dependence, reward-related behavioral tendencies, and lower number of detoxifications., Conclusion: These results seem to be consistent with a shift from goal-directed to habit-driven alcohol use with severity and progression of addiction, complementing preclinical work and informing biological models of addiction. Both reward-related and habit-driven alcohol use were associated with lower number of detoxifications, perhaps stemming from more benign course for the reward-related and lack of treatment engagement for the habit-related alcohol abuse group. Future work should further explore the role of habit in this and other addictive disorders, and in obsessive-compulsive related disorders.

Objective: Impulsivity and compulsivity have been implicated as important transdiagnostic dimensional phenotypes with potential relevance to addiction. We aimed to develop a model that conceptualizes these constructs as overlapping dimensional phenotypes and test whether different components of this model explain the co-occurrence of addictive and related behaviors., Methods: A large sample of adults (N = 487) was recruited through Amazon's Mechanical Turk and completed self-report questionnaires measuring impulsivity, intolerance of uncertainty, obsessive beliefs, and the severity of 6 addictive and related behaviors. Hierarchical clustering was used to organize addictive behaviors into homogenous groups reflecting their co-occurrence. Structural equation modeling was used to evaluate fit of the hypothesized bifactor model of impulsivity and compulsivity and determine the proportion of variance explained in the co-occurrence of addictive and related behaviors by each component of the model., Results: Addictive and related behaviors clustered into 2 distinct groups: Impulse-Control Problems, consisting of harmful alcohol use, pathological gambling, and compulsive buying, and Obsessive-Compulsive-Related Problems, consisting of obsessive-compulsive symptoms, binge eating, and internet addiction. The hypothesized bifactor model of impulsivity and compulsivity provided the best empirical fit, with 3 uncorrelated factors corresponding to a general Disinhibition dimension, and specific Impulsivity and Compulsivity dimensions. These dimensional phenotypes uniquely and additively explained 39.9% and 68.7% of the total variance in Impulse-Control Problems and Obsessive-Compulsive-Related Problems., Conclusion: A model of impulsivity and compulsivity that represents these constructs as overlapping dimensional phenotypes has important implications for understanding addictive and related behaviors in terms of shared etiology, comorbidity, and potential transdiagnostic treatments.

Objective: We aimed to determine whether individuals with obsessive-compulsive disorder (OCD) and demographically matched healthy individuals can be clustered into distinct clinical subtypes based on dimensional measures of their self-reported compulsivity (OBQ-44 and IUS-12) and impulsivity (UPPS-P)., Methods: Participants (n=217) were 103 patients with a clinical diagnosis of OCD; 79 individuals from the community who were "OCD-likely" according to self-report (Obsessive-Compulsive Inventory-Revised scores equal or greater than 21); and 35 healthy controls. All data were collected between 2013 and 2015 using self-report measures that assessed different aspects of compulsivity and impulsivity. Principal component analysis revealed two components broadly representing an individual's level of compulsivity and impulsivity. Unsupervised clustering grouped participants into four subgroups, each representing one part of an orthogonal compulsive-impulsive phenotype., Results: Clustering converged to yield four subgroups: one group low on both compulsivity and impulsivity, comprised mostly of healthy controls and demonstrating the lowest OCD symptom severity; two groups showing roughly equal clinical severity, but with opposing drivers (i.e., high compulsivity and low impulsivity, and vice versa); and a final group high on both compulsivity and impulsivity and recording the highest clinical severity. Notably, the largest cluster of individuals with OCD was characterized by high impulsivity and low compulsivity. Our results suggest that both impulsivity and compulsivity mediate obsessive-compulsive symptomatology., Conclusions: Individuals with OCD can be clustered into distinct subtypes based on measures of compulsivity and impulsivity, with the latter being found to be one of the more defining characteristics of the disorder. These dimensions may serve as viable and novel treatment targets.

Background Lithium and quetiapine are considered standard maintenance agents for bipolar disorder yet it is unclear how their efficacy compares with each other. Aims To investigate the differential effect of lithium and quetiapine on symptoms of depression, mania, general functioning, global illness severity and quality of life in patients with recently stabilised first-episode mania. Method Maintenance trial of patients with first-episode mania stabilised on a combination of lithium and quetiapine, subsequently randomised to lithium or quetiapine monotherapy (up to 800 mg/day) and followed up for 1 year. (Trial registration: Australian and New Zealand Clinical Trials Registry - ACTRN12607000639426.) Results In total, 61 individuals were randomised. Within mixed-model repeated measures analyses, significant omnibus treatment × visit interactions were observed for measures of overall psychopathology, psychotic symptoms and functioning. Planned and post hoc comparisons further demonstrated the superiority of lithium treatment over quetiapine. Conclusions In people with first-episode mania treated with a combination of lithium and quetiapine, continuation treatment with lithium rather than quetiapine is superior in terms of mean levels of symptoms during a 1-year evolution., Competing Interests: Declaration of interestThis study was supported by an unrestricted grant from AstraZeneca. R.D., M.H. and K.H. worked on a study that has received research support by AstraZeneca. M.B. has received grant/research support from the NIH, Cooperative Research Centre, Simons Autism Foundation, Cancer Council of Victoria, Stanley Medical Research Foundation, MBF, NHMRC, Beyond Blue, Rotary Health, Geelong Medical Research Foundation, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Meat and Livestock Board, Organon, Novartis, Mayne Pharma, Servier and Woolworths, has been a speaker for AstraZeneca, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Janssen-Cilag, Lundbeck, Merck, Pfizer, Sanofi Synthelabo, Servier, Solvay and Wyeth, and served as a consultant to AstraZeneca, Bioadvantex, Bristol Myers Squibb, Eli Lilly, Glaxo SmithKline, Janssen-Cilag, Lundbeck Merck and Servier. C.M. has received a grant/research support from Eli Lilly and AstraZeneca, Janssen Cilag and Sanofi Aventis, and served as a consultant to AstraZeneca and Eli Lilly. P.D.M. has received investigator initiated research grants from AstraZeneca, Janssen-Cilag, Eli Lilly and BMS. He has received honoraria for educational events from Janssen-Cilag, Eli Lilly, BMS, AstraZeneca, Pfizer and Lundbeck. C.P. has participated on Advisory Boards for Janssen-Cilag, AstraZeneca, Lundbeck and Servier, has received honoraria for talks presented at educational meetings organised by AstraZeneca, Janssen-Cilag, Eli-Lilly, Pfizer, Lundbeck and Shire., (© The Royal College of Psychiatrists 2017.)

Aims To determine the rates and associated illness characteristics of obsessive-compulsive disorder (OCD) patients who describe their symptoms as either rewarding or habitual., Methods: Seventy-three treatment-seeking OCD patients had their dominant compulsive behavior assessed with a structured interview (the Temporal Impulsive-Compulsive Scale-Revised) to track the progression of rewarding (ie, gain in positive affect), aversive (ie, decrease in negative affect), and neutral (or non-affective) states and a self-report scale (the Self-Report Habit Index) to evaluate their habitual features. Additional measures included structured diagnostic interviews for axis I and II disorders, measures of OCD symptoms severity, and a battery of instruments to comprehensively assess relevant aspects of sensitivity to reward and fear., Results: Almost half (49%) of our OCD patients (particularly washers) endorsed that they anticipated obtaining a reward (ie, positive affect) from the enactment of their dominant compulsive behavior. Washers stood out in that their positive affects during and after compulsive behaviors were highly (and positively) correlated with duration of illness. In contrast, habit strength did not differ between washers, checkers, and arrangers, although it also correlated with duration of illness among checkers. Furthermore, the severity of OCD and comorbidity with impulse control disorders predicted up to 35% of the variance in the habit strength of OCD behaviors., Conclusion: Compulsive washing may be more clearly characterized by problems in reward processing. In contrast, duration of checking, severity of OCD, and comorbidity with impulse control disorders shape compulsive behaviors by imparting them with habitual tendencies.

We investigated the morphology of multiple brain regions in a rare sample of 15 very heavy cannabis users with minimal psychiatric comorbidity or significant exposure to other substances (compared with 15 age- and IQ-matched non-cannabis-using controls) using manual techniques. Heavy cannabis users demonstrated smaller hippocampus and amygdala volumes, but no alterations of the orbitofrontal and anterior- and paracingulate cortices, or the pituitary gland. These findings indicate that chronic cannabis use has a selective and detrimental impact on the morphology of the mediotemporal lobe., (Royal College of Psychiatrists.)