BackgroundThe aim was to investigate the personality profile of bipolar disorder I and II, and healthy controls, and to study whether personality influences the course of bipolar disorder.MethodsOne hundred ten patients with bipolar disorder I, 85 patients with bipolar disorder II, and 86 healthy individuals had their personality profile assessed using the Swedish universities Scales of Personality (SSP), an instrument developed to explore personality-related vulnerabilities and correlates of psychiatric disorders. Patients were followed prospectively for 2 years. To assess the impact of Neuroticism, Aggressiveness, and Disinhibition on illness course, we performed logistic regressions with the outcome variables mood episodes (depressive, hypo/manic, mixed), suicide attempts, violence, and the number of sick leave days.ResultsBipolar disorder I and II demonstrated higher global measures of Neuroticism, Aggressiveness, and Disinhibition as compared with healthy controls. A third of the patients scored ≥1 SD above the population-based normative mean on the global neuroticism measure. The two subtypes of bipolar disorder were, however, undistinguishable on all of the personality traits. In the unadjusted model, higher neuroticism at baseline predicted future depressive episodes and suicide attempts/violent behavior, but this association disappeared when adjusting for baseline depressive symptoms as assessed with MADRS.ConclusionsA significant minority of the patients scored ≥1 SD above the population mean on the global measures of Neuroticism, Aggressiveness and Disinhibition; scores this high are usually evident clinically. Yet, the personality profile does not seem to have prognostic value over a 2-year period.

ObjectivesBipolar disorder is accompanied by cognitive impairments, which persists during euthymic phases. The purpose of the present study was to identify those neuropsychological tests that most reliably tell euthymic bipolar patients and controls apart, and to clarify the extent to which these cognitive impairments are clinically significant as judged from neuropsychological norms.MethodsPatients with bipolar disorder (type I: n = 64; type II: n = 44) and controls (n = 86) were examined with a comprehensive neuropsychological test battery yielding 47 measures of executive functioning, speed, memory, and verbal skills. Multivariate analysis was used to build a model of cognitive performance with the ability to expose underlying trends in data and to reveal cognitive differences between patients and controls.ResultsPatients with bipolar disorder and controls were partially separated by one predictive component of cognitive performance. Additionally, the relative relevance of each cognitive measure for such separation was decided. Cognitive tests measuring set shifting, inhibition, fluency, and searching (e.g., Trail Making Test, Color-Word) had strongest discriminating ability and most reliably detected cognitive impairments in the patient group.ConclusionsBoth bipolar disorder type I and type II were associated with cognitive impairment that for a sizeable minority is significant in a clinical neuropsychological sense. We demonstrate a combination of neuropsychological tests that reliably detect cognitive impairment in bipolar disorder.

Background: Bipolar disorder is associated with significant functional deficits including occupational functioning. Despite the high rates of unemployment and sick leave in the patient population, only a limited number of studies have examined factors associated with occupational functioning in bipolar disorder. The aim of the study was to investigate the relative importance of demographic, clinical, and neuropsychological factors on occupational dysfunction in bipolar disorder. Methods: A sample of 120 partially or fully remitted bipolar disorder I and II patients were included in the study. Patients were stratified into an active and an inactive group based on the number of hours per week working or studying. Active (n = 86) and inactive (n = 34) patients were compared with respect to demographic factors, clinical characteristics, medication, measures of psychosocial functioning, and cognitive functioning (i.e., IQ and executive functions). No other cognitive domains were examined. Results: Univariate analyses revealed better overall cognitive function in active patients in terms of IQ and executive functioning. However, only executive functioning accounted for a significant amount of the variance in occupational status when other significant predictors were taken into account. Conclusions: Executive functioning was a more powerful predictor of occupational status in bipolar disorder patients than IQ and other clinical factors, including illness severity.

BackgroundThe efficacy of psychoeducation for bipolar disorder has been demonstrated in clinical trials, but it is not known if the results translate into effectiveness in routine clinical practice. The aim was to determine the effectiveness of psychoeducation for bipolar disorder in a routine clinical setting.MethodWe identified 2819 patients with at least three registrations in the Swedish Quality Assurance Register for Bipolar Disorder. Among those, 402 had not been exposed to psychoeducation at the first visit, but received psychoeducation during any of the following registrations. Using within-individual analyses, the risk of recurrence after having received psychoeducation was compared with the risk prior to psychoeducation.ResultsIn adjusted within-individuals comparisons, periods after psychoeducation was associated with decreased risks of any recurrence [odds ratio (OR) 0.57, 95% CI 0.42–0.78], (hypo-)manic or mixed episodes (OR 0.54, 95% CI 0.39–0.76), depressive episodes (OR 0.63, 95% CI 0.47–0.86), and inpatient care (OR 0.54, 95% CI 0.33–0.86) relative to periods prior to psychoeducation. There was no association with rates of involuntary sectioning or suicide attempts.ConclusionsThe results suggest that psychoeducation for bipolar disorder reduces the risk of mood episodes and inpatient care also when implemented in routine clinical practice.

Whereas the majority of patients performed similar to controls, a subgroup of patients with bipolar disorder differed substantially from healthy controls in the correlation pattern of low-level cognitive abilities. This suggests that cognitive impairment is not a general trait in bipolar disorder but characteristic of a cognitive subgroup. This has important clinical implications for cognitive rehabilitation and remediation.

ObjectiveFrontal cortical abnormalities and executive function impairment co‐occur in bipolar disorder. Recent studies have shown that bipolar subtypes differ in the degree of structural and functional impairments. The relationships between cognitive performance and cortical integrity have not been clarified and might differ across patients with bipolar disorder type I, II, and healthy subjects.MethodUsing a vertex‐wise whole‐brain analysis, we investigated how cortical integrity, as measured by cortical thickness, correlates with executive performance in patients with bipolar disorder type I, II, and controls (N = 160).ResultsWe found focal associations between executive function and cortical thickness in the medial prefrontal cortex in bipolar II patients and controls, but not in bipolar I disorder. In bipolar II patients, we observed additional correlations in lateral prefrontal and occipital regions.ConclusionsOur findings suggest that bipolar disorder patients show altered structure–function relationships, and importantly that those relationships may differ between bipolar subtypes. The findings are line with studies suggesting subtype‐specific neurobiological and cognitive profiles. This study contributes to a better understanding of brain structure–function relationships in bipolar disorder and gives important insights into the neuropathophysiology of diagnostic subtypes.

Postsynaptic density is reduced in schizophrenia, and risk variants increasing complement component 4A (C4A) gene expression are linked to excessive synapse elimination. In two independent cohorts, we show that cerebrospinal fluid (CSF) C4A concentration is elevated in patients with first-episode psychosis (FEP) who develop schizophrenia (FEP-SCZ: median 0.41 fmol/ul [CI = 0.34–0.45], FEP-non-SCZ: median 0.29 fmol/ul [CI = 0.22–0.35], healthy controls: median 0.28 [CI = 0.24–0.33]). We show that the CSF elevation of C4A in FEP-SCZ exceeds what can be expected from genetic risk variance in the C4 locus, and in patient-derived cellular models we identify a mechanism dependent on the disease-associated cytokines interleukin (IL)−1beta and IL-6 to selectively increase neuronal C4A mRNA expression. In patient-derived CSF, we confirm that IL-1beta correlates with C4A controlled for genetically predicted C4A RNA expression (r = 0.39; CI: 0.01–0.68). These results suggest a role of C4A in early schizophrenia pathophysiology.

The etiopathology of bipolar disorder is largely unknown. We collected cerebrospinal fluid (CSF) samples from two independent case-control cohorts (total n=351) to identify proteins associated with bipolar disorder. A panel of 92 proteins targeted towards central nervous system processes identified two proteins that replicated across the cohorts: the CSF concentrations of testican-1 were lower, and the CSF concentrations of C-type lectin domain family 1 member B were higher (CLEC1B), in cases than controls. In a restricted subgroup analysis, we compared only bipolar type 1 with controls and identified two additional proteins that replicated in both cohorts: draxin and tumor necrosis factor receptor superfamily member 21 (TNFRSF21), both lower in cases than controls. This analysis additionally revealed several proteins significantly associated with bipolar type 1 in one cohort, falling just short of replicated statistical significance in the other (tenascin-R, disintegrin and metalloproteinase domain-containing protein 23, cell adhesion molecule 3, RGM domain family member B, plexin-B1, and brorin). Next, we conducted genome-wide association analyses of the case-control-associated proteins. In these analyses, we found associations with the voltage-gated calcium channel subunit CACNG4, and the lipid droplet-associated gene PLIN5 with CSF concentrations of TNFRSF21 and CLEC1B, respectively. The reported proteins are involved in neuronal cell-cell and cell-matrix interactions, particularly in the developing brain, and in pathways of importance for lithium's mechanism of action. In summary, we report four novel CSF protein associations with bipolar disorder, replicated in two independent case-control cohorts, shedding new light on the central nervous system processes implicated in bipolar disorder.