Neurocognitive dysfunction is present in early BD and is clinically significant for a proportion of patients. Our findings also suggest that neurocognitive dysfunction may increase with illness progression.

The functional significance of neuropsychological impairment is discussed. Differences regarding some aspects of executive function may be related to psychomotor speed, and not primarily to dysexecutive functioning. ERP results must be interpreted with caution, but the differences found in MMN latency and amplitudes may be related to fronto-temporal circuitry underlying pre-attentive stimulus change detection as measured by MMN, and are discussed in relation to previous research on MMN in other neuropsychiatric conditions.

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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.

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.

ObjectiveTo examine which subgroups of DSM-IV bipolar disorder (BD) [BD type I (BD-I) or BD type II (BD-II), and subgroups based on history of psychosis, presenting polarity, and age at onset] differentiate best regarding neurocognitive measures.MethodsA total of 199 patients with BD were characterized by clinical and neurocognitive features. The distribution of subgroups in this sample was: BD-I, 64% and BD-II, 36%; 60% had a history of psychosis; 57% had depression as the presenting polarity; 61% had an early onset of BD, 25% had a mid onset, and 14% had a late onset. We used multivariate regression analyses to assess relationships between neurocognitive variables and clinical subgroups.ResultsBoth BD-I diagnosis and elevated presenting polarity were related to impairments in verbal memory, with elevated presenting polarity explaining more of the variance in this cognitive domain (22.5%). History of psychosis and BD-I diagnosis were both related to impairment in semantic fluency, with history of psychosis explaining more of the variance (11.6%).ConclusionPoor performance in verbal memory appears to be associated with an elevated presenting polarity, and poor performance in semantic fluency appears to be associated with a lifetime history of psychosis.

Studies of social functioning in severe mental disorders are disadvantaged by the multitude of different assessment instruments in use. The present study aims to establish reliability and validity of the Norwegian version of the Social Functioning Scale (SFS) and to examine social functioning in bipolar disorder (BD) compared to schizophrenia (SZ) and healthy controls (HC). SFS, a 76 item questionnaire divided into seven subscales measuring various aspects of daily life functioning, was administered to samples diagnosed with BD (n = 100) or SZ (n = 100) and to HC (n = 100), recruited from the ongoing Tematic Organized Psychosis (TOP) study. Reliability analyses prove adequate psychometric properties both for the composite full scale score (α: 0.81) as well as for the seven subscale scores (α: 0.60-0.88). Principal component analysis of the subscales confirms a one-component structure, explaining 59% of the variance. Although significantly correlated with the Global Assessment of Functioning, our results indicate that the SFS measures different aspects of social functioning, is less influenced by demographic and clinical characteristics, but differentiates at the same time significantly BD from SZ. Thus, SFS adds valuable information as a supplement to standard clinician-rated assessment tools of social functioning, suited both for research and clinical work.

Severe clinical course of BD was associated with receipt of disability benefit. Occupational outcome was unrelated to PAS, premorbid and current IQ, as well as decline in IQ. This suggests that the persistence of severe clinical symptoms, rather than global cognitive functioning, determines occupational outcome in BD and emphasizes the protective potential of early and continuous clinical treatment.