Empirical evidence for discrete neurocognitive subgroups in bipolar disorder: clinical implications

Abstract

Background Recent data suggest trait-like neurocognitive impairments in bipolar disorder (BPD), with deficits about 1 s.D. below average, less severe than deficits noted in schizophrenia. The frequency of significant impairment in BPD is approximately 60%, with 40% of patients characterized as cognitively spared. This contrasts with a more homogeneous presentation in schizophrenia. It is not understood why some BPD patients develop deficits while others do not. Method A total of 136 patients with BPD completed the MATRICS Consensus Cognitive Battery and data were entered into hierarchical cluster analyses to: (1) determine the optimal number of clusters (subgroups) that fit the sample; and (2) assign subjects to a specific cluster based on individual profiles. We then compared subgroups on several clinical factors and real-world community functioning. Results Three distinct neurocognitive subgroups were found: (1) an intact group with performance comparable with healthy controls on all domains but with superior social cognition; (2) a selective impairment group with moderate deficits on processing speed, attention, verbal learning and social cognition and normal functioning in other domains; and (3) a global impairment group with severe deficits across all cognitive domains comparable with deficits in schizophrenia. Conclusions These results suggest the presence of multiple cognitive subgroups in BPD with unique profiles and begin to address the relationships between these subgroups, several clinical factors and functional outcome. Next steps will include using these data to help guide future efforts to target these disabling symptoms with treatment.

Neuropsychological Clustering in Bipolar and Major Depressive Disorder

“…The presence of patients with mood disorders in all three clusters suggests that individual characteristics may play a more prominent role in cognitive functioning than diagnostic category. This conclusion supports the findings of previous cluster studies, which identify variable levels of cognitive impairment in samples with BD and MDD (Burdick et al, 2014;Hermens et al, 2011). The distribution of clusters identified in the present study was also similar to that revealed by other similar investigations of psychiatric samples.…”

“…The hierarchical clustering procedure used in this study was similar to that described in previous investigations of similar populations (Burdick et al, 2014;Hermens et al, 2011). Patterns of neuropsychological performance were identified using Ward's method of minimum variance (Ward, 1963) with a 586 C. Cotrena et al…”

Genetic disruption of ankyrin-G in adult mouse forebrain causes cortical synapse alteration and behavior reminiscent of bipolar disorder

“…The drug × gene × time interactions are significant, indicating cKO mice may bear different sensitivity to methylphenidate from control, although the key point is that there were increases overall, not decreases. We did not detect severe deficits in cognitive tests, and cognition is generally reported to be more severely altered in schizophrenia than bipolar disorder (27,47). Future studies could include more sensitive and sophisticated cognitive function tests.…”

Cognitive function and lifetime features of depression and bipolar disorder in a large population sample: Cross-sectional study of 143,828 UK Biobank participants

“…(20,21). It is therefore apparent that the cognitive phenotype associated 379 with mood disorder is diverse, both in clinical settings and in the broader population.…”