Executive functioning in familial bipolar I disorder patients and their unaffected relatives

Objective:To compare the executive function of patients with familial bipolar I disorder (BP-I) with a history of psychotic symptoms to their first-degree relatives and normal controls.Methods:Three domains of executive function: response inhibition, working memory, and cognitive set shifting were assessed in 44 familial patients with a lifetime diagnosis of BP-I who had experienced psychotic symptoms, 42 of their unaffected first-degree relatives, and 47 controls.Results:Bipolar disorder patients and their unaffected relatives had significantly worse scores for response inhibition compared to healthy controls. The groups did not differ in working memory or cognitive set shifting.Conclusions:Impairments in response inhibition are associated with both psychotic bipolar disorder and genetic liability for this illness. Our results indicate that deficits in this specific domain of executive functioning are a promising candidate endophenotype for psychotic bipolar disorder.