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.

The augmentation of clozapine with ECT is a safe and effective treatment option. Further research is required to determine the persistence of the improvement and the potential need for maintenance treatments.

The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative was devised to identify a neurocognitive battery to be used in clinical trials targeting cognition in schizophrenia, a process, which resulted in the MATRICS Consensus Cognitive Battery (MCCB). The MCCB has been selected by the United States Food and Drug Administration to be used as the primary outcome measure in registry trials for cognitive agents in schizophrenia. Given the clinical and cognitive overlap between schizophrenia and bipolar disorder (BPD), it is likely that any compound shown to have cognitive benefits in schizophrenia will subsequently be tested in BPD. Unlike the MCCB for schizophrenia, there remains no consensus regarding outcome measures if cognitive trials were to be undertaken in BPD. The utility of the MCCB in BPD has not yet been systematically investigated. We administered the MCCB to 80 bipolar I patients; 37 were strictly euthymic and 43 were symptomatic. We compared their performance with a demographically matched healthy sample (n=148) on seven MCCB domains, and the composite. BPD patients were statistically significantly impaired on five of seven MCCB domains at levels consistent with meta-analytic studies of cognition in BPD. In contrast, patients' performance was less impaired on the Reasoning and Problem-solving and Social Cognition domains, differences that did not survive statistical correction for multiple testing. Symptomatic status only modestly influenced performance. These data suggest that the MCCB, devised for use in schizophrenia, may also represent a useful outcome measure in cognitive trials for BPD. Additional studies should address important psychometric features such as repeatability and potential practice and/or ceiling effects.