Anja Vaskinn

Neurocognitive Dysfunction in Bipolar and Schizophrenia Spectrum Disorders Depends on History of Psychosis Rather Than Diagnostic Group

OBJECTIVES Neurocognitive dysfunction is milder in bipolar disorders than in schizophrenia spectrum disorders, supporting a dimensional approach to severe mental disorders. The aim of this study was to investigate the role of lifetime history of psychosis for neurocognitive functioning across these disorders. We asked whether neurocognitive dysfunction in bipolar and schizophrenia spectrum disorders depends more on history of psychosis than diagnostic category or subtype. METHODS A sample of individuals with schizophrenia (n=102), schizoaffective disorder (n=27), and bipolar disorder (I or II) with history of psychosis (n=75) and without history of psychosis (n=61) and healthy controls (n=280), from a large ongoing study on severe mental disorder, were included. Neurocognitive function was measured with a comprehensive neuropsychological test battery. RESULTS Compared with controls, all 3 groups with a history of psychosis performed poorer across neurocognitive measures, while the bipolar group without a history of psychosis was only impaired on a measure of processing speed. The groups with a history of psychosis did not differ from each other but performed poorer than the group without a history of psychosis on a number of neurocognitive measures. These neurocognitive group differences were of a magnitude expected to have clinical significance. In the bipolar sample, history of psychosis explained more of the neurocognitive variance than bipolar diagnostic subtype. CONCLUSIONS Our findings suggest that neurocognitive dysfunction in bipolar and schizophrenia spectrum disorders is determined more by history of psychosis than by Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) diagnostic category or subtype, supporting a more dimensional approach in future diagnostic systems.

Neurocognitive profiles in bipolar I and bipolar II disorder: differences in pattern and magnitude of dysfunction.

OBJECTIVES Studies on neurocognitive functioning in bipolar disorder, reporting deficits in memory, attention, and executive functioning, have primarily focused on bipolar I disorder. The aim of this study was to examine whether patients with bipolar I and bipolar II disorder have different neurocognitive profiles. METHODS Forty-two patients with bipolar I disorder, 31 patients with bipolar II and 124 healthy controls, from a large ongoing study on psychotic disorders, were included. Neurocognitive function was measured with a comprehensive neuropsychological test battery. RESULTS The bipolar I group performed significantly poorer than the healthy control group and the bipolar II group on all measures of memory. Compared with the control group, the bipolar I group also had significantly reduced performance on most measures of attention and executive functioning, while the bipolar II group only had a significantly reduced performance on a subset of these measures. On average, 24% of the bipolar I group had clinically significant cognitive impairment (< or =1.5 SD below the control group mean) across measures, compared with 13% of the bipolar II group. CONCLUSIONS Patients with bipolar I and bipolar II disorder in this study have different neurocognitive profiles. Bipolar I patients have more widespread cognitive dysfunction both in pattern and magnitude, and a higher proportion has clinically significant cognitive impairments compared with patients with bipolar II. This may suggest neurobiological differences between the two bipolar subgroups.

Apathy is associated with executive functioning in first episode psychosis

BackgroundThe underlying nature of negative symptoms in psychosis is poorly understood. Investigation of the relationship between the different negative subsymptoms and neurocognition is one approach to understand more of the underlying nature. Apathy, one of the subsymptoms, is also a common symptom in other brain disorders. Its association with neurocognition, in particular executive functioning, is well documented in other brain disorders, but only studied in one former study of chronic patients with schizophrenia. This study investigates the association between apathy and neurocognitive functioning in patients with first episode psychosis (FEP), with the hypothesis that apathy is more associated with tests representing executive function than tests representing other neurocognitive domains.MethodsSeventy-one FEP patients were assessed with an extensive neuropsychological test battery. Level of apathy was assessed with the abridged Apathy Evaluation Scale (AES-C-Apathy).ResultsAES-C-Apathy was only significantly associated with tests from the executive domain [Semantic fluency (r = .37, p < .01), Phonetic fluency (r = .25, p < .05)] and working memory [Letter Number Span (r = .26; p =< .05)]; the first two representing the initiation part of executive function. Confounding variables such as co-occuring depression, positive symptoms or use of antipsychotic medication did not significantly influence the results.ConclusionWe replicated in FEP patients the relationship between apathy and executive functioning reported in another study for chronic patients with schizophrenia. We also found apathy in FEP to have the same relationship to executive functioning, as assessed with the Verbal fluency tests, as that reported in patients with other brain disorders, pointing to a common underlying nature of this symptom across disorders.

The effect of gender on emotion perception in schizophrenia and bipolar disorder

Objective:  Impaired emotion perception is documented for schizophrenia, but findings have been mixed for bipolar disorder. In healthy samples females perform better than males. This study compared emotion perception in schizophrenia and bipolar disorder and investigated the effects of gender.

Predictors of medication adherence in patients with schizophrenia and bipolar disorder

Objective:  To investigate potential risk factors for medication non‐adherence in patients with schizophrenia and bipolar disorder.

Delusions Are Associated With Poor Cognitive Insight in Schizophrenia

The purpose of the study was to investigate the relationship between the symptoms delusions and hallucinations measured by the Positive and Negative Syndrome Scale and cognitive insight as assessed with the Beck Cognitive Insight Scale (BCIS) in patients with schizophrenia. The BCIS is based on 2 subscales, self-reflectiveness and self-certainty, measuring objectivity, reflectiveness and openness to feedback, and mental flexibility. Overall cognitive insight was defined as the difference between self-reflectiveness and self-certainty. This cross-sectional study of 143 patients showed that the occurrence of delusions is associated with low self-reflectiveness and high self-certainty, reflecting low cognitive insight. Hallucinations in the absence of delusions were associated with high self-reflectiveness and low self-certainty, possibly reflecting more open-mindedness and higher cognitive insight. The present findings suggest that delusions are associated with low cognitive insight, whereas solitary hallucinations may be associated with high cognitive insight.

Emotion perception and learning potential: mediators between neurocognition and social problem-solving in schizophrenia?

Social cognition and learning potential have been proposed as mediating variables between neurocognition and functional outcome in schizophrenia. The present study examined this relation in a schizophrenia group (N = 26) with normal IQ. Neurocognition was measured with a composite score from tests of verbal learning, psychomotor speed, and executive functioning. Functional outcome was defined as social problem-solving skills and assessed with a role-play test. Social cognition was indexed by tests of visual and auditory emotion perception; and learning potential by estimating a gain score using a triple administration of the WCST. Neurocognition was confirmed to be a strong predictor of social problem-solving, and emotion perception was related to both neurocognition and social problem-solving. When controlling for emotion perception, the association between neurocognition and social problem-solving was weakened, implying a mediating role of emotion perception. Learning potential was not significantly related to neurocognition or social problem-solving, and thus not found to mediate the studied relation. In conclusion, our study indicates that emotion perception is a mediator between neurocognition and functional outcome as assessed with a social problem-solving task and thus a key factor in understanding functional outcome of schizophrenia.

Illicit drug use in patients with psychotic disorders compared with that in the general population: a cross-sectional study.

Objective:  Prevalence estimates of illicit drug use in psychotic disorders vary between studies, and only a few studies compared prevalence estimates with those in the general population.

Psychosocial function in schizophrenia and bipolar disorder: Relationship to neurocognition and clinical symptoms

In line with a dimensional approach to psychopathology, we examined whether psychosocial function and its relationship to neurocognition and clinical symptoms differ across schizophrenia and bipolar disorder subgroups with and without a history of affective or psychotic episodes. From the TOP study, a heterogeneous sample of individuals with schizophrenia spectrum disorders without (n = 60) and with a history of affective episodes (n = 54); individuals with bipolar spectrum disorders with (n = 64) and without a history of psychosis (n = 56) and healthy controls (n = 268) participated. Psychosocial functioning was measured with the Social Functioning Scale (self-rated) and the Global Assessment of Functioning Scale (clinician-rated), neurocognition with a comprehensive neuropsychological test battery, and symptoms with Inventory of Depressive Symptomatology, Young Mania Rating Scale, and Positive and Negative Syndrome Scale. Clinician-rated functioning was poorer in schizophrenia groups than in bipolar groups, but self-rated functioning was similar across all clinical groups and poorer than in controls. Neurocognition and current clinical symptoms were associated with psychosocial function in bivariate analyses, but current symptoms had a greater independent contribution to functioning than neurocognition across clinical groups in multivariate analyses. Despite differences in neurocognition and psychosocial function, groups showed the same pattern in prediction of functioning irrespective of DSM-IV or clinical definition.

Sex differences in neuropsychological performance and social functioning in schizophrenia and bipolar disorder.

OBJECTIVE To investigate sex differences in neurocognition and social functioning in schizophrenia and bipolar disorder and the possible role of sex as a moderator of this relationship. METHOD Participants with schizophrenia (60 women/94 men), bipolar I disorder (55 women/51 men), and healthy controls (158 women/182 men) were assessed with an extensive neuropsychological test battery and a social functioning questionnaire. RESULTS We found significant main effects of sex for neuropsychological tests (p < .001, η² = 0.10) and social functioning (p < .001, η² = 0.05), with men scoring below women. Women performed better than men for all neuropsychological tests (except attention and working memory). Both clinical groups performed below healthy controls for all neuropsychological tests (except attention). Post hoc comparisons of persons with schizophrenia and healthy controls yielded significant interaction effects (p < .05) for three neuropsychological tests (California Verbal Learning Test II [CVLT-II], Color-Word Interference, and Interference/Switching), with men with schizophrenia being disproportionally disadvantaged compared with their female counterparts. Regression analyses investigating sex as a moderator between neurocognition and social functioning showed that neurocognition predicted social functioning in schizophrenia, whereas sex predicted social functioning in healthy controls. Sex was not a moderator in any of the three groups. CONCLUSIONS This study is the first to find neurocognitive sex differences for bipolar disorder and replicated previous findings for schizophrenia. The data did not support the hypothesis that sex is a moderator between neurocognition and social functioning. Clinical implications include the use of different cognitive remediation strategies based on sex.