Neurocognitive impairments and their relationship with psychosocial functioning in euthymic bipolar II disorder.

The aim of this study was to compare neurocognitive functioning between euthymic patients with bipolar I disorder (BDI), bipolar II disorder (BDII), and healthy controls. An additional aim was to estimate the relationship between neurocognitive impairments and psychosocial functioning. Eighty-seven patients with BDI (n = 48) or BDII (n = 39) and 39 healthy controls were included. All subjects completed an extensive neurocognitive battery. Psychosocial functioning was assessed using the General Assessment of Functioning. Patients with BDII performed more poorly than did the controls in measures of psychomotor speed, verbal memory, and executive functioning. Patient groups did not show differences in any of the cognitive measures assessed. The performance in trail-making test B was the only independent predictor of psychosocial functioning in both patient groups. Patients with BDII have cognitive impairments, and this has a negative influence on their functional outcome. Our results bring additional support to the notion that BDII disorder is not a merely mild type of BDI.