Cognitive and inflammatory heterogeneity in severe mental illness: Translating findings from blood to brain.

Recent findings link cognitive impairment and inflammatory-immune dysregulation in schizophrenia (SZ) and bipolar (BD) spectrum disorders. However, heterogeneity and translation between the periphery and central (blood-to-brain) mechanisms remains a challenge. Starting with a large SZ, BD and healthy control cohort (n = 1235), we aimed to i) identify candidate peripheral markers (n = 25) associated with cognitive domains (n = 9) and elucidate heterogenous immune-cognitive patterns, ii) evaluate the regulation of candidate markers using human induced pluripotent stem cell (iPSC)-derived astrocytes and neural progenitor cells (n = 10), and iii) evaluate candidate marker messenger RNA expression in leukocytes using microarray in available data from a subsample of the main cohort (n = 776), and in available RNA-sequencing deconvolution analysis of postmortem brain samples (n = 474) from the CommonMind Consortium (CMC). We identified transdiagnostic subgroups based on covariance between cognitive domains (measures of speed and verbal learning) and peripheral markers reflecting inflammatory response (CRP, sTNFR1, YKL-40), innate immune activation (MIF) and extracellular matrix remodelling (YKL-40, CatS). Of the candidate markers there was considerable variance in secretion of YKL-40 in iPSC-derived astrocytes and neural progenitor cells in SZ compared to HC. Further, we provide evidence of dysregulated RNA expression of genes encoding YKL-40 and related signalling pathways in a high neuroinflammatory subgroup in the postmortem brain samples. Our findings suggest a relationship between peripheral inflammatory-immune activity and cognitive impairment, and highlight YKL-40 as a potential marker of cognitive functioning in a subgroup of individuals with severe mental illness.

Sex differences in social cognition among individuals with schizophrenia and in healthy control participants: a secondary analysis of published data.

PURPOSE: Sex differences are present among individuals experiencing schizophrenia. Whether these differences extend to social cognition is unclear. In this study, we investigated sex differences in emotion perception, social perception and theory of mind (ToM). METHODS: We examined sex differences between males and females with schizophrenia on five social cognitive tests. Healthy male and female control participants were included to examine if any sex difference was illness-specific. Emotion perception was measured with Pictures of Facial Affect (PFA) and Emotion in Biological Motion (EmoBio); social perception with the Relationships Across Domains Test (RAD); and ToM with the Movie for the Assessment of Social Cognition (MASC) and Hinting Task. RESULTS: Two-way analyses of variance revealed overall group differences for all tests, with healthy controls outperforming individuals with schizophrenia. Significant sex effects were present for PFA and Hinting Task. There were no significant interaction effects. Within-group independent samples t-tests yielded one significant sex difference, i.e., among healthy controls for PFA. CONCLUSIONS: Females had better facial emotion perception than males. This sex difference was statistically significant among healthy controls and medium-large among individuals experiencing schizophrenia. There were no significant sex differences for other social cognitive domains. The study did not find evidence for a general female advantage in social cognition.

Course of intellectual functioning in schizophrenia and bipolar disorder: a 10-year follow-up study.

BACKGROUND: Intellectual functioning (IQ) is lower in schizophrenia patients compared to healthy controls, with bipolar patients intermediate between the two. Declines in IQ mark the onset of schizophrenia, while stability is generally found post-onset. There are to date few studies on long-term IQ development in bipolar disorder. This study presents 10-year follow-up data on IQ, including premorbid IQ estimates, to track the developmental course from pre-onset levels to long-term outcomes in both patient groups compared to healthy controls. METHODS: We included 139 participants with schizophrenia, 76 with bipolar disorder and 125 healthy controls. Mixed model analyses were used to estimate developmental slopes for IQ scores from estimated premorbid level (NART IQ) through baseline (WASI IQ) measured within 12 months post-onset, to 10-year follow-up (WASI IQ), with pairwise group comparisons. The best fit was found using a model with a breakpoint at baseline assessment. RESULTS: Only the schizophrenia group had significant declines from estimated premorbid to baseline IQ levels compared to controls. When comparing patient groups, schizophrenia patients had steeper declines than the bipolar group. Increases in IQ were found in all groups over the follow-up period. CONCLUSIONS: Trajectories of IQ from premorbid level to 10-year follow-up indicated declines from estimated premorbid level to illness onset in both patient groups, followed by increases during the follow-up period. Schizophrenia patients had a steeper decline than bipolar patients. During follow-up, increases indicate developmental improvement for both patient groups, but with a maintained lag compared to healthy controls due to lower premorbid levels.

The "zipper model of empathy" applied to violence in schizophrenia: A search for social cognitive underpinnings of lack of empathic behavior.

BACKGROUND: The "zipper model of empathy" has been proposed for psychopathy. It postulates that empathic behavior may fail to arise due to impaired facial emotion recognition. In this study, we examined if the model may be of relevance for schizophrenia. METHODS: In a sample of participants with schizophrenia and a history of severe interpersonal violence, associations between measures of social cognition (emotion recognition, theory of mind) and aspects of psychopathy (lack of empathy, lack of remorse) were investigated. A non-violent sample experiencing schizophrenia served as a control group. RESULTS: Correlation analyses revealed a specific and statistically significant association between facial emotion recognition and lack of empathy in the violent sample. Follow-up analyses identified that neutral emotions were of particular importance. Logistic regression analyses confirmed that impairments in facial emotion recognition predicted levels of empathy in the violent sample experiencing schizophrenia. CONCLUSIONS: Our results suggest that the "zipper model of empathy" may be relevant for schizophrenia. The findings further point to the potential benefit of including social cognitive training in the treatment of persons with schizophrenia and a history of interpersonal aggression.

Theory of mind in schizophrenia: a comparison of subgroups with low and high IQ.

BACKGROUND: Social cognitive impairment is common in schizophrenia, but it is unclear if it is present in individuals with high IQ. This study compared theory of mind (ToM) in schizophrenia participants with low or high IQ to healthy controls. METHODS: One hundred and nineteen participants (71 healthy controls, 17 high IQ (IQ ≥115), and 31 low IQ (IQ ≤95) schizophrenia participants) were assessed with the Movie for the Assessment of Social Cognition, providing scores for total, cognitive, and affective ToM, along with overmentalizing, undermentalizing, and no-mentalizing errors. IQ was measured with Wechsler Abbreviated Scale of Intelligence; clinical symptoms with the Positive and Negative Syndrome Scale. RESULTS: Healthy controls performed better than the low IQ schizophrenia group for all ToM scores, and better than the high IQ schizophrenia group for the total score and under- and no-mentalizing errors. The high IQ group made fewer overmentalizing errors and had better total and cognitive ToM than the low IQ group. Their number of overmentalizing errors was indistinguishable from healthy controls. CONCLUSION: Global ToM impairment was present in the low IQ schizophrenia group. Overmentalizing was not present in the high IQ group and appears related to lower IQ. Intact higher-level reasoning may prevent the high IQ group from making overmentalizing errors, through self-monitoring or inhibition. We propose that high IQ patients are chiefly impaired in lower-level ToM, whereas low IQ patients also have impaired higher-level ToM. Conceivably, this specific impairment could help explain the lower functioning reported in persons with intact IQ.

Significant association between intracranial volume and verbal intellectual abilities in patients with schizophrenia and a history of birth asphyxia.

BACKGROUND: The etiology of schizophrenia (SZ) is proposed to include an interplay between a genetic risk for disease development and the biological environment of pregnancy and birth, where early adversities may contribute to the poorer developmental outcome. We investigated whether a history of birth asphyxia (ASP) moderates the relationship between intracranial volume (ICV) and intelligence in SZ, bipolar disorder (BD) and healthy controls (HC). METHODS: Two hundred seventy-nine adult patients (18-42 years) on the SZ and BD spectrums and 216 HC were evaluated for ASP based on information from the Medical Birth Registry of Norway. Participants underwent structural magnetic resonance imaging (MRI) to estimate ICV and intelligence quotient (IQ) assessment using the Wechsler Abbreviated Scale of Intelligence (WASI). Multiple linear regressions were used for analyses. RESULTS: We found a significant three-way interaction (ICV × ASP × diagnosis) on the outcome variable, IQ, indicating that the correlation between ICV and IQ was stronger in patients with SZ who experienced ASP compared to SZ patients without ASP. This moderation by ASP was not found in BD or HC groups. In patients with SZ, the interaction between ICV and a history of the ASP was specifically related to the verbal subcomponent of IQ as measured by WASI. CONCLUSIONS: The significant positive association between ICV and IQ in patients with SZ who had experienced ASP might indicate abnormal neurodevelopment. Our findings give support for ICV together with verbal intellectual abilities as clinically relevant markers that can be added to prediction tools to enhance evaluations of SZ risk.

Sleep disturbance mediates the link between childhood trauma and clinical outcome in severe mental disorders.

BACKGROUND: The experience of childhood trauma is linked to more severe symptoms and poorer functioning in severe mental disorders; however, the mechanisms behind this are poorly understood. We investigate the relationship between childhood trauma and sleep disturbances in severe mental disorders including the role of sleep disturbances in mediating the relationship between childhood trauma and the severity of clinical symptoms and poorer functioning. METHODS: In total, 766 participants with schizophrenia-spectrum (n = 418) or bipolar disorders (n = 348) were assessed with the Childhood Trauma Questionnaire. Sleep disturbances were assessed through the sleep items in the self-reported Inventory of Depressive Symptoms. Clinical symptoms and functioning were assessed with The Positive and Negative Syndrome Scale and the Global Assessment of Functioning Scale. Mediation analyses using ordinary least squares regression were conducted to test if sleep disturbances mediated the relationship between childhood trauma and the severity of clinical symptoms and poorer functioning. RESULTS: Symptoms of insomnia, but not hypersomnia or delayed sleep phase, were significantly more frequent in participants with childhood trauma experiences compared to those without. Physical abuse, emotional abuse, and emotional neglect were significantly associated with insomnia symptoms. Insomnia symptoms partly mediate the relationship between childhood trauma and the severity of positive and depressive/anxiety symptoms, in addition to poorer functioning. CONCLUSION: We found frequent co-occurrence of childhood trauma history and current insomnia in severe mental disorders. Insomnia partly mediated the relationship between childhood trauma and the severity of clinical symptoms and functional impairment.

An exploration of theory of mind performance among men convicted of rape.

Several of the known risk factors for sexual violence concern a lack of capacity for engaging in mutually satisfying interpersonal relationships. Socio-cognitive deficits may be approached from a theory of mind (ToM) perspective, where lack of ability to attribute mental states to others is seen as the core feature. This study focuses on imprisoned men (n = 26) convicted of rape against an adult. A video-based measure of ToM (MASC) was applied, depicting social interaction in a dynamic real-life setting. The results showed that the rape-convicted men have a markedly inferior ability to infer the mental states of others. Clinical as well as theoretical implications of the findings are discussed.

Obstetric complications and intelligence in patients on the schizophrenia-bipolar spectrum and healthy participants.

BACKGROUND: Whether severe obstetric complications (OCs), which harm neural function in offspring, contribute to impaired cognition found in psychiatric disorders is currently unknown. Here, we sought to evaluate how a history of severe OCs is associated with cognitive functioning, indicated by Intelligence Quotient (IQ). METHODS: We evaluated the associations of a history of OCs and IQ in 622 healthy controls (HC) and 870 patients on the schizophrenia (SCZ) - bipolar disorder (BIP) spectrum from the ongoing Thematically Organized Psychosis study cohort, Oslo, Norway. Participants underwent assessments using the NART (premorbid IQ) and the WASI (current IQ). Information about OCs was obtained from the Medical Birth Registry of Norway. Multiple linear regression models were used for analysis. RESULTS: Severe OCs were equally common across groups. SCZ patients with OCs had lower performances on both premorbid and current IQ measures, compared to those without OCs. However, having experienced more than one co-occurring severe OC was associated with lower current IQ in all groups. CONCLUSIONS: Severe OCs were associated with lower IQ in the SCZ group and in the BIP and HC groups, but only if they had experienced more than one severe OC. Low IQ might be a neurodevelopmental marker for SCZ; wherein, severe OCs influence cognitive abilities and increase the risk of developing SCZ. Considering OCs as a variable of neurodevelopmental risk for severe mental illness may promote the development of neuroprotective interventions, improve outcome in vulnerable newborns and advance our ability to make clinical prognoses.

Cognitive Heterogeneity across Schizophrenia and Bipolar Disorder: A Cluster Analysis of Intellectual Trajectories.

OBJECTIVE: Cognitive dysfunction cut across diagnostic categories and is present in both schizophrenia and bipolar disorder, although with considerable heterogeneity in both disorders. This study examined if distinct cognitive subgroups could be identified across schizophrenia and bipolar disorder based on the intellectual trajectory from the premorbid phase to after illness onset. METHOD: Three hundred and ninety-eight individuals with schizophrenia (n = 223) or bipolar I disorder (n = 175) underwent clinical and neuropsychological assessment. Hierarchical and k-means cluster analyses using premorbid (National Adult Reading Test) and current IQ (Wechsler Abbreviated Scale of Intelligence) estimates were performed for each diagnostic category, and the whole sample collapsed. Resulting clusters were compared on neuropsychological, functional, and clinical variables. Healthy controls (n = 476) were included for analyses of neuropsychological performance. RESULTS: Cluster analyses consistently yielded three clusters: a relatively intact group (36% of whole sample), an intermediate group with mild cognitive impairment (44%), and an impaired group with global deficits (20%). The clusters were validated by multinomial logistic regression and differed significantly for neuropsychological, functional, and clinical measures. The relatively intact group (32% of the schizophrenia sample and 42% of the bipolar sample) performed below healthy controls for speeded neuropsychological tests. CONCLUSIONS: Three cognitive clusters were identified across schizophrenia and bipolar disorder using premorbid and current IQ estimates. Groups differed for clinical, functional, and neuropsychological variables, implying their meaningfulness. One-third of the schizophrenia sample belonged to the relatively intact group, highlighting that neuropsychological assessment is needed for the precise characterization of the individual.

Social Perception Predicts Awareness of Illness in Persons With Schizophrenia.

Lack of clinical insight in patients with schizophrenia is an obstacle to optimal treatment. Social cognition is one of several variables central to insight deficits in schizophrenia. The aim of this study was to investigate clinical insight in relation to one domain of social cognition, social perception, while controlling for effects of nonsocial cognition and symptom severity. Clinical insight was measured in 55 patients with schizophrenia or schizoaffective disorder, using the Birchwood Insight Scale. Relationships across domains were used to assess social perception. Social perception predicted one of three subscales of clinical insight, "awareness of illness," and was the only unique contributor to this subscale. This indicates that social perception is linked to clinical insight through awareness of illness. More research is needed to fully understand the relationship between social and nonsocial cognition and symptoms in relation to clinical insight.

A randomized controlled trial of training of affect recognition (TAR) in schizophrenia shows lasting effects for theory of mind.

Schizophrenia is characterized by social cognitive impairments that predict functioning. Social cognitive training aims to target these impairments. Although it can improve the targeted social cognitive domain, it is unclear if the training generalizes to non-targeted domains and to functioning, with lasting effects. This randomized controlled trial examined the effect of a targeted facial affect recognition training program, Training of Affect Recognition (TAR), in persons with schizophrenia. Individuals with schizophrenia were randomized to receive treatment as usual and TAR (n = 24) or treatment as usual (n = 24) after assessments with a comprehensive protocol at baseline (T1). Participants were reassessed immediately after the intervention period (T2: after 8 weeks) and at 3-month follow-up (T3). The protocol included tests of social cognition (facial or body affect recognition, theory of mind), nonsocial cognition (Matrics Consensus Cognitive Battery), clinical symptoms (Positive and Negative Syndrome Scale, Calgary Depression Scale for Schizophrenia), functioning (self-reported, social or nonsocial functional capacity), self-esteem, self-efficacy and insight. Linear mixed models yielded a significant group × time interaction effect for a non-targeted social cognitive domain (theory of mind) and a trend-level effect for social functional capacity with the intervention group performing better over time. No beneficial effects on nonsocial cognition, other measures of functioning, clinical symptoms, or self-esteem/self-efficacy appeared for the TAR program. This study provides evidence for transfer and durability effects of facial affect recognition training to theory of mind, but also highlights the need for additional treatments to achieve functional benefits.

Perceived and experienced stigma in first-episode psychosis: A 1-year follow-up study.

OBJECTIVES: Perceived/experienced stigma and its relationship with clinical outcome were investigated across the first year of treatment in a large sample with first-episode psychosis (FEP). METHODS: FEP participants (n=112) in the TOP study were investigated at baseline and 1-year follow-up. Perceived/experienced stigma was measured with items from the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), assessing problems because of barriers and hindrances, and living with dignity because of attitudes and actions of others. Clinical outcome included: symptoms, global functioning, self-rated disability and self-rated life satisfaction. RESULTS: In the total sample, 46% perceived/experienced stigma at baseline, which decreased significantly to 32% at 1-year follow-up. Perceived/experienced stigma was present in 1/5 at both time-points (Sustained stigma), in 2/5 at only one time-point (Transient stigma), and in 2/5 it was not present at either time-point (No stigma). Compared to the No stigma group, the Sustained stigma group had significantly higher levels of positive, excited and depressive symptoms and self-rated disability, as well as lower levels of global functioning and life satisfaction at 1year follow-up, while the Transient stigma group only had poorer functioning and higher self-rated disability. Yet the outcome variables improved across the first year of treatment in all three stigma groups. CONCLUSION: Perceived/experienced stigma was common in FEP, yet the rate decreased across the first year of treatment. Although there was some clinical improvement across the first year of treatment irrespective of stigma, stigma was related to poorer clinical outcome in a bidirectional manner. This suggests that perceived/experienced stigma is an important target in the early stages of treatment.

Theory of mind in schizophrenia and bipolar disorder: psychometric properties of the Norwegian version of the Hinting Task.

ABSTRACTIntroduction: The quality of measures used to assess theory of mind (ToM) in severe mental illness has not been sufficiently investigated. This study evaluated the psychometric properties of the Norwegian version of the Hinting Task in schizophrenia, bipolar I and II disorder and healthy controls.Methods: The study included 90 patients and 183 healthy controls. Internal consistency, ceiling effects, discriminatory power and concurrent and construct validity were investigated.Results: The Hinting Task displayed adequate levels of internal consistency for schizophrenia and bipolar I disorder. Ceiling effects emerged in all groups except the schizophrenia group. Schizophrenia patients scored significantly lower than all other groups, but no other significant group differences were detected. In the schizophrenia group, the Hinting Task's concurrent validity was substantiated by significant correlations with measures of neurocognition, symptoms and functional capacity. In the bipolar disorder groups, however, only a few significant relationships were found. Correlations between the Hinting Task and a measure of emotion recognition indicated that construct validity was higher for schizophrenia than bipolar disorder.Conclusions: The results suggest that the Norwegian Hinting Task is suited for use in schizophrenia research and assessment, but caution is warranted when using the test for other populations.

Body language reading of emotion and outcome in schizophrenia.

INTRODUCTION: Although considered a promising design for testing social cognition, it is not clear to what extent the EmoBio test of emotion recognition actually predicts community functioning. It is also not clear whether the test measures something unique or different from nonsocial cognition. The present study tests whether EmoBio accounts for GAF function score and two operationalised community outcome measures. The study also analyses cognitive predictors of EmoBio performance, testing whether stimulus modality affects prediction. METHODS: Eighty-three patients with schizophrenia were tested with EmoBio, the cognitive battery MCCB and WAIS-IV. RESULTS: EmoBio accounted for a significant portion of variance in all three outcome measures. Only EmoBio predicted Lifetime Relationship status, and EmoBio remained a significant predictor of Independent living beyond non-social cognition. All cognitive measures contributed significantly to the variance in EmoBio, but entered together explained only a third of total variance. CONCLUSION: The study shows that emotion recognition accounts for community outcome. There was no clear effect of test-modality in predicting EmoBio performance, indicating no method invariance problem with EmoBio. It also indicates that the mechanisms underlying impaired social cognition in schizophrenia are different from the hypothesised non-verbal learning deficits in the disorder.

Increased prevalence of psychopathy and childhood trauma in homicide offenders with schizophrenia compared to nonviolent individuals with schizophrenia.

Purpose: Schizophrenia is associated with an increased homicide risk. Personality pathology, particularly antisocial personality disorder and psychopathic traits, has been associated with increased violence risk in schizophrenia. Childhood trauma, more specifically physical abuse, has been associated with violence risk in healthy populations and in individuals with mental illness. It is, however, unclear how childhood trauma relates to homicide in schizophrenia. This is, to our knowledge, the first study to concurrently examine personality pathology and childhood trauma in a group consisting solely of homicide offenders with schizophrenia (HOS). HOS is compared to nonviolent participants with the same diagnosis (non-HOS). Additionally, currently assessed demographical and clinical characteristics of a Norwegian sample of HOS are reported. Materials and methods: Two groups of participants with schizophrenia were recruited in collaboration with in and outpatient clinics across Norway, HOS (n= 26) and non-HOS (n= 28). Assessments of personality pathology and childhood trauma were conducted, and information about clinical and demographical characteristics was registered. Results: HOS participants had significantly higher psychopathy scores, and more frequently reported moderate to severe childhood physical abuse than non-HOS participants. When simultaneously added to a logistic regression model, only psychopathy uniquely contributed to explaining group membership. Conclusions: Psychopathy and physical abuse was more prevalent among HOS participants compared to non-HOS, but only psychopathy independently predicted homicidal status. These results confirm the importance of including an evaluation of psychopathic traits in violence risk assessments of individuals with schizophrenia.

Emotion perception, non-social cognition and symptoms as predictors of theory of mind in schizophrenia.

BACKGROUND: Theory of mind (ToM) can be divided into cognitive and affective ToM, and a distinction can be made between overmentalizing and undermentalizing errors. Research has shown that ToM in schizophrenia is associated with non-social and social cognition, and with clinical symptoms. In this study, we investigate cognitive and clinical predictors of different ToM processes. METHODS: Ninety-one individuals with schizophrenia participated. ToM was measured with the Movie for the Assessment of Social Cognition (MASC) yielding six scores (total ToM, cognitive ToM, affective ToM, overmentalizing errors, undermentalizing errors and no mentalizing errors). Neurocognition was indexed by a composite score based on the non-social cognitive tests in the MATRICS Consensus Cognitive Battery (MCCB). Emotion perception was measured with Emotion in Biological Motion (EmoBio), a point-light walker task. Clinical symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Seventy-one healthy control (HC) participants completed the MASC. RESULTS: Individuals with schizophrenia showed large impairments compared to HC for all MASC scores, except overmentalizing errors. Hierarchical regression analyses with the six different MASC scores as dependent variables revealed that MCCB was a significant predictor of all MASC scores, explaining 8-18% of the variance. EmoBio increased the explained variance significantly, to 17-28%, except for overmentalizing errors. PANSS excited symptoms increased explained variance for total ToM, affective ToM and no mentalizing errors. DISCUSSION: Both social and non-social cognition were significant predictors of ToM. Overmentalizing was only predicted by non-social cognition. Excited symptoms contributed to overall and affective ToM, and to no mentalizing errors.

Self-rated disability in first treated episode of psychosis: A 1-year follow-up study.

OBJECTIVES: Knowledge about self-rated disability over time in psychotic disorders is limited. How self-rated disability relates to clinician-rated global functioning, self-rated life satisfaction and symptomatology was investigated across the first year of treatment in early psychosis. METHODS: Participants with first treated episode of psychosis (n = 115) were investigated at baseline and 1-year follow-up. Self-rated Disability was measured with World Health Organization- Disability Assessment Schedule 2.0. Clinician-rated global functioning, self-rated life satisfaction, and symptomatology were measured with appropriate scales. RESULTS: Average self-rated disability in first-treated episode of psychosis was high, corresponding with the 10% highest in a general population sample. However, 37% were not disabled at a clinically significant level after one year. Self-rated disability was highest in the two social domains (Getting along with people and Participation in society), but improved significantly from baseline to 1-year. At 1-year follow-up self-rated disability had significant weak to medium correlations with clinician-rated global functioning and positive symptoms, and mainly medium to strong correlations with life satisfaction and depressive symptoms. Yet only baseline depression significantly predicted disability after one year. CONCLUSION: Self-rated disability in first treated episode of psychosis is high, but improves across the first year, indicating signs of early recovery. Moreover, self-rated disability is related, but distinct from clinician-rated global functioning and self-rated life satisfaction, suggesting that self-rated disability should also be assessed in order to more fully describe outcomes in first episode psychosis. The findings highlight the need for specialised treatment of depression and social disability in early psychosis.

Impaired neuropsychological profile in homicide offenders with schizophrenia.

BACKGROUND: Our ability to predict and prevent homicides committed by individuals with schizophrenia is limited. Cognitive impairments are associated with poorer functional outcome in schizophrenia, possibly also homicide. The aim of the current study was to investigate global and specific cognition among homicide offenders with schizophrenia (HOS). METHODS: Twenty-six HOS were compared to 28 individuals with schizophrenia and no history of violence (non-HOS), and a group of healthy controls (HC, n = 151). HOS and non-HOS participants were recruited from in- and outpatient units across Norway. An extensive neuropsychological test battery was administered. RESULTS: HOS participants performed significantly weaker than HC in all cognitive domains. Further, statistically significant differences between HOS and non-HOS participants were found for IQ (d = 0.52) and verbal learning (d = 0.82), with larger impairments in the HOS compared to the non-HOS group. CONCLUSIONS: Our results indicate that HOS participants show clinically significant impairments in global and specific cognition.

Enhancing tolerability of a measure of social perception in schizophrenia: comparison of short and long Norwegian versions of the Relationships Across Domains test.

INTRODUCTION: Relationship perception focuses on social interactions, is reduced in schizophrenia and is related to daily functioning. It can be assessed with the Relationships Across Domains (RAD) test, built on Relational Models Theory which states that people use four relational models to interpret social interaction. RAD is time consuming, low on tolerability and only used in English-speaking countries. We evaluated the psychometric properties of a translated, abbreviated Norwegian version. METHODS: Sixty-two schizophrenia participants and 56 healthy controls underwent assessments of social and non-social cognition. The schizophrenia group completed functional and clinical measures. RAD's internal consistency was investigated with Cronbach's alphas, group differences with logistic regressions and associations between study variables with Pearson's correlations. RESULTS: RAD was reduced from 25 (Cronbach's alpha = .809) to 12 vignettes (Cronbach's alpha = .815). Schizophrenia participants had significant impairments, with larger effect sizes for the full version. Associations of RAD with study variables were similar for the two versions: smaller for clinical measures and larger for functional and cognitive measures. Results were comparable to results for the English version. CONCLUSIONS: The length of the Norwegian RAD was reduced while retaining its psychometric properties, which were similar to the English version. This suggests the test's cross-cultural utility.