Genetic Risk And Outcome Of Psychosis Research Articles

Exploring the Interactions Between Psychotic Symptoms, Cognition, and Environmental Risk Factors: A Bayesian Analysis of Networks.

Psychotic disorders (PDs) have huge personal and societal impact, and efforts to improve outcomes in patients are continuously needed. Environmental risk factors (ERFs), especially modifiable risk factors, are important to study because they pose a target for intervention and prevention. No studies have investigated ERFs, cognition, and psychotic symptoms together in a network approach. We explored interactions between 3 important ERFs (tobacco smoking, cannabis use, and childhood trauma), 6 cognitive domains, and 3 dimensions of symptoms in psychosis. From the Genetic Risk and Outcome of Psychosis (GROUP) cohort, we used data from patients, siblings, and healthy controls to construct networks using Bayesian analyses of all 12 variables. We constructed networks of the combined sample and of patients and siblings separately. We found that tobacco smoking was directly associated with cognition and psychotic symptoms. The cognitive variable processing speed was the most central node, connecting clusters of psychotic symptoms and substance use through the variables of positive symptoms and tobacco smoking. Comparing the networks of patients and siblings, we found that networks were relatively similar between patients and siblings. Our results support a potential central role of processing speed deficits in PDs. Findings highlight the importance of integrating tobacco smoking as potential ERFs in the context of PDs and to broaden the perspective from cannabis discontinuation to smoking cessation programs in patients or people at risk of PDs.

The association between clinical, sociodemographic, familial, and environmental factors and treatment resistance in schizophrenia: A machine-learning-based approach

BackgroundPrediction of treatment resistance in schizophrenia (TRS) would be helpful to reduce the duration of ineffective treatment and avoid delays in clozapine initiation. We applied machine learning to identify clinical, sociodemographic, familial, and environmental variables that are associated with TRS and could potentially predict TRS in the future. Study designBaseline and follow-up data on trait(-like) variables from the Genetic Risk and Outcome of Psychosis (GROUP) study were used. For the main analysis, we selected patients with non-affective psychotic disorders who met TRS (n = 200) or antipsychotic-responsive criteria (n = 423) throughout the study. For a sensitivity analysis, we only selected patients who met TRS (n = 76) or antipsychotic-responsive criteria (n = 123) at follow-up but not at baseline. Random forest models were trained to predict TRS in both datasets. SHapley Additive exPlanation values were used to examine the variables' contributions to the prediction. Study resultsPremorbid functioning, age at onset, and educational degree were most consistently associated with TRS across both analyses. Marital status, current household, intelligence quotient, number of moves, and family loading score for substance abuse also consistently contributed to the prediction of TRS in the main or sensitivity analysis. The diagnostic performance of our models was modest (area under the curve: 0.66–0.69). ConclusionsWe demonstrate that various clinical, sociodemographic, familial, and environmental variables are associated with TRS. Our models only showed modest performance in predicting TRS. Prospective large multi-centre studies are needed to validate our findings and investigate whether the model's performance can be improved by adding data from different modalities.

Six-year trajectories and associated factors of positive and negative symptoms in schizophrenia patients, siblings, and controls: Genetic Risk and Outcome of Psychosis (GROUP) study

Positive and negative symptoms are prominent but heterogeneous characteristics of schizophrenia spectrum disorder (SSD). Within the framework of the Genetic Risk and Outcome of Psychosis (GROUP) longitudinal cohort study, we aimed to distinguish and identify the genetic and non-genetics predictors of homogenous subgroups of the long-term course of positive and negative symptoms in SSD patients (n = 1119) and their unaffected siblings (n = 1059) in comparison to controls (n = 586). Data were collected at baseline, and after 3- and 6-year follow-ups. Group-based trajectory modeling was applied to identify latent subgroups using positive and negative symptoms or schizotypy scores. A multinomial random-effects logistic regression model was used to identify predictors of latent subgroups. Patients had decreasing, increasing, and relapsing symptoms course. Unaffected siblings and healthy controls had three to four subgroups characterized by stable, decreasing, or increasing schizotypy. PRSSCZ did not predict the latent subgroups. Baseline symptoms severity in patients, premorbid adjustment, depressive symptoms, and quality of life in siblings predicted long-term trajectories while were nonsignificant in controls. In conclusion, up to four homogenous latent subgroups of symptom course can be distinguished within patients, siblings, and controls, while non-genetic factors are the main factors associated with the latent subgroups.

Deep Clinical Phenotyping of Schizophrenia Spectrum Disorders Using Data-Driven Methods: Marching towards Precision Psychiatry.

Heterogeneity is the main challenge in the traditional classification of mental disorders, including schizophrenia spectrum disorders (SSD). This can be partly attributed to the absence of objective diagnostic criteria and the multidimensional nature of symptoms and their associated factors. This article provides an overview of findings from the Genetic Risk and Outcome of Psychosis (GROUP) cohort study on the deep clinical phenotyping of schizophrenia spectrum disorders targeting positive and negative symptoms, cognitive impairments and psychosocial functioning. Three to four latent subtypes of positive and negative symptoms were identified in patients, siblings and controls, whereas four to six latent cognitive subtypes were identified. Five latent subtypes of psychosocial function-multidimensional social inclusion and premorbid adjustment-were also identified in patients. We discovered that the identified subtypes had mixed profiles and exhibited stable, deteriorating, relapsing and ameliorating longitudinal courses over time. Baseline positive and negative symptoms, premorbid adjustment, psychotic-like experiences, health-related quality of life and PRSSCZ were found to be the strong predictors of the identified subtypes. Our findings are comprehensive, novel and of clinical interest for precisely identifying high-risk population groups, patients with good or poor disease prognosis and the selection of optimal intervention, ultimately fostering precision psychiatry by tackling diagnostic and treatment selection challenges pertaining to heterogeneity.

Age-Related Social Cognitive Performance in Individuals With Psychotic Disorders and Their First-Degree Relatives.

Social cognitive impairment is a recognized feature of psychotic disorders. However, potential age-related differences in social cognitive impairment have rarely been studied. Data came from 905 individuals with a psychotic disorder, 966 unaffected siblings, and 544 never-psychotic controls aged 18-55 who participated in the Genetic Risk and Outcome of Psychosis (GROUP) study. Multilevel linear models were fitted to study group main effects and the interaction between group and age on emotion perception and processing (EPP; degraded facial affect recognition) and theory of mind (ToM; hinting task) performance. Age-related differences in the association between socio-demographic and clinical factors, and EPP and ToM were also explored. Across groups, EPP performance was associated with age (β = -0.02, z = -7.60, 95% CI: -0.02, -0.01, P < .001), with older participants performing worse than younger ones. A significant group-by-age interaction on ToM (X2(2) = 13.15, P = .001) indicated that older patients performed better than younger ones, while no age-related difference in performance was apparent among siblings and controls. In patients, the association between negative symptoms and ToM was stronger for younger than older patients (z = 2.16, P = .03). The findings point to different age-related performance patterns on tests of 2 key social cognitive domains. ToM performance was better in older individuals, although this effect was only observed for patients. EPP was less accurate in older compared with younger individuals. These findings have implications with respect to when social cognitive training should be offered to patients.

Personal recovery suits us all: A study in patients with non-affective psychosis, unaffected siblings and healthy controls.

Personal recovery transcends illness and is a unifying human experience. Core elements in personal recovery are hope, meaning, and rebuilding oneself. Here we aim to investigate whether factors associated with personal recovery in patients with non-affective psychosis, unaffected siblings and healthy controls are similar. We investigated the association between personal recovery and resilience, social support, socio-demographic and illness-related variables in 580 patients, 630 siblings, and 351 healthy controls who participated in the Genetic Risk and Outcome of Psychosis (GROUP) study. Bi-variate associations between personal recovery and individual variables were assessed and multiple linear regression analyses were performed to estimate the proportion of variance in personal recovery that could be accounted for by the predictors and to investigate which predictors independently added to the model. Positive self was significantly and independently associated with personal recovery in all three groups. Pro-active action taking also seems to be important. Social functioning significantly contributed to explained variance in patients and siblings. Regarding illness-related factors, depressive symptoms had impact on personal recovery in both patients and siblings, whereas positive symptoms only did in siblings. The findings imply that not only personal recovery itself, but also some associated factors are universally human and suit us all. This means that patients and non-patients share supportive factors of personal recovery which may help to reach mutual understanding. Recovery-oriented practices and mental health services might be more effective when focusing also on improving self-image, functional coping styles and generating social interaction, next to the reduction of affective symptoms.

Attachment Style and Self-Experience: The Association Between Attachment Style and Self-Reported Altered Self-Experience in Patients With Psychotic Disorders, Unaffected Siblings, and Healthy Controls.

The present study aimed to examine the cross-sectional association between attachment style and self-reported disturbed self-awareness (disturbed sense of mineness of experiences) and depersonalization (disturbed sense of first-person perspective) in patients with psychotic disorders, unaffected siblings, and healthy controls. Data pertain to a subsample of the GROUP (Genetic Risk and Outcome of Psychosis) study. We found positive associations between anxious attachment and disturbed self-awareness and depersonalization across participants with different psychosis vulnerability. We also found a positive association between avoidant attachment and depersonalization, although on a trend level. Findings indicate that attachment style is associated with self-reported disturbed self-awareness and depersonalization over and above the influence of psychotic or depressive experiences in people across the vulnerability spectrum of psychosis. This supports the importance of attachment style, self-awareness, and depersonalization as potential targets in prevention and treatment interventions in patients with psychotic disorders or those with increased vulnerability.

The association between attachment style and social functioning in patients with non-affective psychotic disorders, unaffected siblings and healthy controls

ObjectiveIn patients with psychotic disorders, insecure attachment styles and impaired social functioning are highly prevalent. Our aim was to explore the multi-cross-sectional and longitudinal associations between attachment style and social functioning. MethodsThis study was performed in a subsample of 119 patients with non-affective psychotic disorders, 128 unaffected siblings and 66 healthy controls within the Genetic Risk and Outcome of Psychosis (GROUP) Study. Attachment style (using the Psychosis Attachment Measure) and three social functioning domains, namely withdrawal, interpersonal behaviour and pro-social activities as measured with the Social Functioning Scale (SFS) were assessed on two moments in time. Generalized linear mixed models and linear regression models were used. Bonferroni correction for multiple testing was applied. ResultsIn the patient group, a significant negative association was found between avoidant attachment and pro-social functioning. In the sibling and control group, we found significant negative associations between avoidant attachment and the social functioning domains withdrawal and interpersonal behaviour. We also found a significant negative association between anxious attachment and the social functioning domain withdrawal in siblings. Higher levels of insecure anxious attachment at baseline predicted a reduction of the social functioning domain interpersonal behaviour in siblings over a period of three years on a trend level. ConclusionsFindings indicate that levels of insecure attachment are elevated in patients with psychotic disorders and have a negative association with social functioning in both patients, siblings and controls. These findings warrant specific attention for attachment style in the treatment of patients with psychotic disorders and individuals with an increased vulnerability for developing psychosis.

Polygenic risk, familial liability and stress reactivity in psychosis: an experience sampling study.

There is evidence for a polygenic contribution to psychosis. One targetable mechanism through which polygenic variation may impact on individuals and interact with the social environment is stress sensitization, characterized by elevated reactivity to minor stressors in daily life. The current study aimed to investigate whether stress reactivity is modified by polygenic risk score for schizophrenia (PRS) in cases with enduring non-affective psychotic disorder, first-degree relatives of cases, and controls. We used the experience sampling method to assess minor stressors, negative affect, positive affect and psychotic experiences in 96 cases, 79 first-degree relatives, i.e. siblings, and 73 controls at wave 3 of the Dutch Genetic Risk and Outcome of Psychosis (GROUP) study. Genome-wide data were collected at baseline to calculate PRS. We found that associations of momentary stress with psychotic experiences, but not with negative and positive affect, were modified by PRS and group (all pFWE<0.001). In contrast to our hypotheses, siblings with high PRS reported less intense psychotic experiences in response to momentary stress compared to siblings with low PRS. No differences in magnitude of these associations were observed in cases with high v. low level of PRS. By contrast, controls with high PRS showed more intense psychotic experiences in response to stress compared to those with low PRS. This tentatively suggests that polygenic risk may operate in different ways than previously assumed and amplify reactivity to stress in unaffected individuals but operate as a resilience factor in relatives by attenuating their stress reactivity.

The impact of childhood sexual trauma on intimacy and sexuality needs among people with non-affective psychosis

BackgroundChildhood trauma, in particular childhood sexual abuse (CSA), and unmet sexuality and intimacy needs are prevalent among people with psychosis spectrum disorders. The association between CSA and sexuality and intimacy needs over time in adults with psychosis spectrum disorders were examined. MethodPatients (n = 1119) were recruited as part of the Genetic Risk and OUtcome of Psychosis (GROUP) study, a representative cohort of patients with non-affective psychotic disorder. At baseline, three-year and six-year follow-up, sexuality and intimacy needs were assessed with the Camberwell Assessment of Needs. CSA was assessed with the Childhood Trauma Questionnaire. ResultsAt baseline, sexuality (26%) and intimacy (40%) needs were prevalent; 90% of these needs remained unmet. Cross-sectionally, CSA was associated with sexuality needs (OR = 1.68, 95% CI: 1.13-2.04) and intimacy needs (OR = 1.75, 95% CI: 1.04- 1.77). Childhood emotional abuse (CEA) was also cross-sectionally associated with sexuality and intimacy needs. Others forms of trauma were not. Prospectively, CSA predicted incidence of a sexuality need (HR = 2.1, 95% CI: 1.23-3.74) as well as an intimacy need (HR = 1.7, 95% CI: 1.11-2.66), as did CEA (sexuality: HR = 1.8, 95% CI: 1.11-2.89; intimacy: HR = 1.4, 95% CI: 1.03-1.96). CSA and CEA were not associated with persistence of sexuality or intimacy. ConclusionCSA and CEA are associated with a higher prevalence and incidence of sexuality and intimacy needs in patients with psychotic disorders. High rates of unmet sexuality and intimacy needs may indicate an underlying need for trauma-related treatment as well as a need for novel interventions targeting these needs.

The association between smoking behaviour, social cognition and social functioning in patients with a non-affective psychotic disorder: A prospective follow-up study

IntroductionIn patients with psychotic disorders, both tobacco smoking and deficits in social cognition and social functioning are highly prevalent. However, little is known about their relationship in psychosis. The authors sought to evaluate the multi-cross-sectional and longitudinal associations between tobacco smoking, social cognition and social functioning in a large prospective study. MethodsThis study was performed within the Genetic Risk and Outcome of Psychosis (GROUP) Study, a cohort study conducted in patients with non-affective psychosis (N = 1074), their unaffected siblings (N = 1047) and healthy controls (N = 549). At baseline, three years and six years of follow-up, data on tobacco smoking (using the Composite International Diagnostic Review), social cognition (emotion processing and theory of mind) and social functioning were collected. To assess associations between tobacco smoking and social cognition or social functioning, multivariate linear mixed-effects models and multiple linear regression models were used. Bonferroni correction for multiple testing was applied. ResultsA significant positive association was found between smoking and emotion processing (as part of social cognition) in the patient group (estimate = 1.96, SE = 0.6, p = 0.003). However, smoking was significantly negatively associated with participating in pro-social activities compared with non-smoking (estimate = −2.55, SE = 0.9, p = 0.004). Change in smoking behaviour was not associated with social cognition or social functioning in the longitudinal analyses. ConclusionFindings indicate that smoking patients with a non-affective psychotic disorder slightly outperformed their non-smoking peers on a task on social cognition, but participated less in pro-social activities. Commencement or cessation of smoking was not related to social cognition or functioning.

Relationship between social cognition, general cognition, and risk for suicide in individuals with a psychotic disorder

ObjectiveCognitive alterations putatively contribute to the risk for suicide in individuals with psychosis. Yet, a comprehensive assessment of social- and general-cognitive abilities in a large sample is lacking. MethodsSeven-hundred-fifteen individuals diagnosed with a psychotic disorder performed tasks of facial emotion recognition, Theory of Mind, and general cognitive functioning (sustained attention, set-shifting, IQ-tests and verbal learning) as part of the Genetic-Risk-and-Outcome-of-Psychosis (GROUP) study. Presence of past suicide attempt/s and/or current suicidal ideation was reported by 261 individuals and 454 individuals reported no suicide attempt or ideation. We used general linear models to investigate group differences in task performance. All analysis were controlled for age, sex, education, and psychotic symptom severity. ResultsIndividuals with suicide attempt and/or ideation showed better performance on the facial emotion recognition task and lower performance on tasks of sustained attention and verbal learning, compared to individuals without suicide attempt and/or ideation, without a clear effect of attempt or ideation. Theory of Mind performance was also better for individuals with suicide attempt and/or ideation, with largest differences between individuals who reported both attempts and ideation compared to individuals without suicide attempt and/or ideation. No effect of suicide attempt and/or ideation was found on misperception of facial emotions, IQ and set-shifting. Overall, effect sizes were small. ConclusionHigher sensitivity to social-emotional cues together with weakened attentional control and learning capacity was observed in individuals with psychosis and suicide attempt and/or ideation. This may suggest that insufficient capacity for regulating perceived social stress contributes to suicidal thoughts and behavior.

The association between sleep disturbances and negative symptom severity in patients with non-affective psychotic disorders, unaffected siblings and healthy controls

Sleep disturbances in patients with psychotic disorders are common and associated with poor clinical outcomes, but research on negative symptoms is limited. This study aimed to examine the association between subjective sleep disturbances and negative symptoms in 525 patients with non-affective psychotic disorders, 569 unaffected siblings and 265 healthy controls (HC) from the Genetic Risk and Outcome of Psychosis (GROUP) study. Several aspects of subjective sleep disturbances were assessed: sleep satisfaction, sleep onset insomnia, midnocturnal insomnia, early morning insomnia, and hypersomnia. Regression analyses revealed significant negative associations between sleep satisfaction and negative symptoms in all three groups. In addition, significant associations with sleep onset insomnia and hypersomnia were found in patients and with early morning insomnia and hypersomnia in siblings. Exploratory mediation analyses showed that depressive symptoms partly mediated all associations on the subclinical level in siblings and healthy controls, whereas only the association with sleep onset insomnia was mediated in patients. The results of this study implicate specific sleep disturbances and depressive symptoms as potential targets in prevention or intervention strategies focussed on negative symptoms in individuals suffering from, or at risk of non-affective psychotic disorders.

Insight, personality, and symptoms among individuals with psychosis: Cross-sectional and longitudinal relationships

BackgroundReports on the relationship between clinical insight and psychotic symptoms have shown inconsistent results, and the association between clinical insight and personality has rarely been addressed. The aim of this study was to examine whether personality is correlated cross-sectionally with insight level, and longitudinally with change in insight, beyond symptoms. MethodsParticipants were a sub-sample of the Dutch Genetic Risk and Outcome of Psychosis (GROUP) project. Two hundred and eleven participants diagnosed with non-affective psychotic disorders took part in the cross-sectional part of the study, of whom 136 took part in the three-year follow-up assessment. They were administered with self-report Birchwood insight scale and NEO-Five Factor Inventory, and clinicians assessed them according to PANSS and CDS symptoms scales. ResultsCross-sectional analysis showed baseline self-report insight was positively related to neuroticism and agreeableness and negatively related to extraversion. Longitudinal analysis showed change in level of self-reported insight was predicted by baseline-insight and change in symptoms of disorganization. Personality factors did not predict insight change (as measured either by self-report or by clinician assessment). DiscussionThe cross-sectional findings showed self-report insight (as opposed to clinician-rated) is associated with personality traits, suggesting negative affect is related to higher level of insight and that having insight may be influenced by the wish to comply with views of professionals, or a tendency to cover up problems. The longitudinal findings imply that not personality but change in severity of symptoms of disorganization, and possibly other variables, predicts change in insight.

Polygenic risk score for schizophrenia was not associated with glycemic level (HbA1c) in patients with non-affective psychosis: Genetic Risk and Outcome of Psychosis (GROUP) cohort study

IntroductionType 2 diabetes (T2D) is a common comorbidity in patients with schizophrenia (SCZ). The underlying pathophysiologic mechanisms are yet to be fully elucidated, although it can be argued that shared genes, environmental factors or their interaction effect are involved. This study investigated the association between polygenic risk score of SCZ (PRSSCZ) and glycated haemoglobin (HbA1c) while adjusting for polygenic risk score of T2D (PRST2D), and clinical and demographic covariables. MethodsGenotype, clinical and demographic data of 1129 patients with non-affective psychosis were extracted from Genetic Risk and Outcome of Psychosis (GROUP) cohort study. The glycated haemoglobin (HbA1c) was the outcome. PRS was calculated using standard methods. Univariable and multivariable linear regression analyses were applied to estimate associations. Additionally, sensitivity analysis based on multiple imputation was done. After correction for multiple testing, a two-sided p-value ≤.003 was considered to discover evidence for an association. ResultsOf 1129 patients, 75.8% were male with median age of 29 years. The mean (standard deviation) HbA1c level was 35.1 (5.9) mmol/mol. There was no evidence for an association between high HbA1c level and increased PRSSCZ (adjusted regression coefficient (aβ) = 0.69, standard error (SE) = 0.77, p-value = .37). On the other hand, there was evidence for an association between high HbA1c level and increased PRST2D (aβ = 0.93, SE = 0.32, p-value = .004), body mass index (aβ = 0.20, SE = 0.08, p-value = .01), diastolic blood pressure (aβ = 0.08, SE = 0.04, p-value = .03), late age of first psychosis onset (aβ = 0.19, SE = 0.05, p-value = .0004) and male gender (aβ = 1.58, SE = 0.81, p-value = .05). After multiple testing correction, there was evidence for an association between high HbA1c level and late age of first psychosis onset. Evidence for interaction effect between PRSscz and antipsychotics was not observed. The multiple imputation-based sensitivity analysis provided consistent results with complete case analysis. ConclusionsGlycemic dysregulation in patients with SCZ was not associated with PRSSCZ. This suggests that the mechanisms of hyperglycemia or diabetes are at least partly independent from genetic predisposition to SCZ. Our findings show that the change in HbA1c level can be caused by at least in part due to PRST2D, late age of illness onset, male gender, and increased body mass index and diastolic blood pressure.

Childhood trauma and coping in patients with psychotic disorders and obsessive-compulsive symptoms and in un-affected siblings

BackgroundResearch on environmental and individual risk-factors in patients with a psychotic disorder and co-occurring obsessive-compulsive symptoms (OCS) is limited. ObjectiveThis study aimed to examine the role of childhood trauma and coping on the occurrence of OCS in patients with a psychotic disorder and on a subclinical level in siblings. Participants and setting626 patients and 638 siblings from the Genetic Risk and Outcome of Psychosis (GROUP) study were included in the current study. MethodsDifferences between patients and siblings with and without OCS were analyzed with between-group comparisons. Mediation analyses investigated the effect of coping on the association between trauma and OCS severity. ResultsPatients and siblings with OCS reported more childhood traumatic events, particularly sexual (OR = 1.62 / 3.26) and emotional (OR = 1.47 / 2.04) abuse compared to those without OCS. Both patients (d = 0.69) and siblings (d = 0.49) with co-occurring OCS showed a higher tendency for dysfunctional passive coping strategies compared to the group without OCS. The tendency for passive coping mediated the association between sexual and emotional abuse and OCS severity in patients. ConclusionsResults imply that childhood trauma is associated with the presence of co-occurring OCS. Enhancing active coping strategies might have a beneficial effect in the prevention and treatment of co-occurring OCS in patients with psychotic disorders.

Cognition and violent behavior in psychotic disorders: A nationwide case-control study

BackgroundThe excess risk of violence in psychotic disorders may partly be explained by impairments in executive functions (EFs) and theory of mind (ToM). However, previous studies have been limited by composite measures of EFs and small samples of inpatients. MethodsData were collected for the research project Genetic Risk and Outcome of Psychosis (GROUP). Patients with psychotic disorders (N = 891) were recruited from various care settings in the Netherlands. The following neuropsychological tests were administered (targeted cognitive function in parentheses): (i) Continuous Performance Test-HQ (inhibition); (ii) Response Shifting Task (cognitive flexibility); (iii) Wechsler Adult Intelligence Scale, Third Edition (WAIS-III) Block Design subtest (fluid intelligence); (iv) Neuropsychological Assessment Battery (NAB) Mazes Test (planning); (v) Degraded Facial Affect Recognition Task (affective ToM); and (vi) Hinting Task (cognitive ToM). Lifetime violence was ascertained from medical records and patient interviews. We used analysis of covariance to compare the mean scores of violent and nonviolent patients on each test, adjusting for age and sex. ResultsViolent patients performed significantly worse than nonviolent patients on the WAIS-III Block Design subtest (F [1, 847] = 5.12, p = .024), NAB Mazes Test (F [1, 499] = 5.32, p = .022) and Hinting Task (F [1, 839] = 9.38, p = .002). For the other tests, the between-group differences were nonsignificant. Violent behavior explained no more than 1% of the variance in performance on each test. ConclusionImpairments in EFs and ToM are unlikely to provide useful targets for risk assessment and interventions.

Is theory of mind a prerequisite for social interactions? A study in psychotic disorder.

A dominant idea is that impaired capacities for theory of mind (ToM) are the reasons for impairments in social functioning in several conditions, including autism and schizophrenia. In this paper, we present empirical evidence that challenges this influential assumption. We conducted three studies examining the association between ToM and social functioning in participants diagnosed with a non-affective psychotic disorder and healthy individuals. We used both the experience sampling method, a structured diary technique collecting information in daily-life, and a standardised questionnaire to assess social functioning. Analysed data are part of Wave 1 and Wave 3 of the Genetic Risk and Outcome of Psychosis (GROUP) study. Results were highly consistent across studies and showed no significant association between the two constructs. These findings question the leading assumption that social cognition is a prerequisite for social functioning, but rather suggest that social cognition is possibly a result of basic social interactive capacities.

Change in IQ in schizophrenia patients and their siblings: a controlled longitudinal study.

Lower intelligence quotient (IQ) has frequently been reported in patients with schizophrenia. However, it is unclear whether IQ declines (further) after illness onset and what the familial contribution is to this change. Therefore, we investigate IQ changes during the course of illness in patients with non-affective psychosis, their siblings and controls. Data are part of the longitudinal Genetic Risk and Outcome of Psychosis (GROUP) study in the Netherlands and Belgium. Participants underwent three measurements, each approximately 3 years apart. A total of 1022 patients with non-affective psychosis [illness duration: 4.34 (s.d. = 4.50) years], 977 of their siblings, and 565 controls had at least one measure of IQ (estimated from four subtests of the WAIS-III). At baseline, IQ was significantly lower in patients (IQ = 97.8) and siblings (IQ = 108.2; p < 0.0001) than in controls (IQ = 113.0; p < 0.0001), and in patients as compared with siblings (p < 0.0001). Over time, IQ increased in all groups. In siblings, improvement in IQ was significantly more pronounced (+0.7 points/year) than in patients (+0.5 points/year; p < 0.0001) and controls (+0.3 points/year; p < 0.0001). IQ increase was not significantly correlated with improvement in (sub)clinical outcome in any of the groups. During the first 10 years of the illness, IQ increases to a similar (and subtle) extent in a relatively high-functioning group of schizophrenia patients and controls, despite the lower IQ in patients at baseline. In addition, the siblings' IQ was intermediate at baseline, but over time the increase in IQ was more pronounced.

Schizophrenia Patients Show Cognitive Improvements After Smoking Cessation

Schizophrenia Patients Show Cognitive Improvements After Smoking Cessation