Neurocognitive profile of euthymic Japanese patients with bipolar disorder.

AIM: Neurocognitive impairment is one of the core symptoms of bipolar disorder (BD). The MATRICS Cognitive Consensus Battery (MCCB) is a potential consensus assessment tool to evaluate cognitive function in patients with BD. Here, we report on cognitive deficits evaluated using the MCCB Japanese version (MCCB-J) in euthymic Japanese patients with BD, and compare them with scores in previous studies. METHODS: We compared neurocognitive function in 25 patients with euthymic BD and 53 healthy controls (HC). Additionally, we searched all available databases for studies that have evaluated cognitive function in BD using the MCCB, and conducted a meta-analysis. RESULTS: Canonical discriminant analysis revealed significant differences in MCCB-J domain scores between BD and HC. Patients with BD performed significantly worse on visual learning, social cognition, speed of processing, and MCCB composite scores. Our meta-analysis revealed that patients with BD performed worse than HC, as reflected by MCCB composite scores and scores on all seven cognitive domains. However, there are differences in the cognitive deficits identified in previous studies compared with our participants, particularly social cognition. CONCLUSION: As reported in previous studies, neurocognitive deficits were observed in Japanese euthymic BD patients assessed using the MCCB-J. Further study is needed to clarify whether differences in social cognition between this study and previous studies are a result of coping mechanisms for social settings in Japanese populations.

Altered strategy in short-term memory for pictures in children with attention-deficit/hyperactivity disorder: a near-infrared spectroscopy study.

Strategy in short-term memory for serially presented pictures shifts gradually from a non-phonological to a phonological method as memory ability increases during typical childhood development. However, little is known about the development of this strategic change in children with attention-deficit/hyperactivity disorder (ADHD). To understand the neural basis of ADHD, we investigated short-term memory strategies using near-infrared spectroscopy. ADHD children aged from 6 to 12 years and age- and sex-matched control children were assessed in this study. Regional activity was monitored in the left ventrolateral prefrontal cortex to assess strategies used during short-term memory for visual or phonological objects. We examined the hypothesis that the strategic methods used would be correlated with memory ability. Higher memory ability and the phonological strategy were significantly correlated in the control group but not in the ADHD group. Intriguingly, ADHD children receiving methylphenidate treatment exhibited increased use of phonological strategy compared with those without. In conclusion, we found evidence of an altered strategy in short-term memory in ADHD children. The modulatory effect of methylphenidate indicates its therapeutic efficacy.