Neurocognitive function in unaffected first-degree relatives of patients with bipolar disorder: a preliminary report.

Abstract

Patients with remitted bipolar disorder (BD) have persistent impairments in neuropsychological function, particularly in the domains of executive control and declarative memory [Br J Psychiatry 180 (2002) 293]. If these were the phenotypic expression of genetic vulnerability to BD, then healthy subjects with a genetic predisposition to BD would be expected to display the same deficits. This study, therefore, examined neuropsychological function in healthy first-degree relatives of patients with BD. A cross-sectional design was employed to compare the performance of 17 unaffected first-degree relatives of BD patients and 17 demographically matched controls on a range of neuropsychological tests. Relatives were significantly impaired on Backward Digit Span, Spatial Span and on tasks of visuospatial declarative memory in comparison with controls. Psychomotor performance and verbal declarative memory were intact, as were non-working memory aspects of executive performance. The selective deficits in executive control and declarative memory exhibited by relatives in this study have previously been reported in euthymic BD patients suggesting they may be useful endophenotypic markers of genetic vulnerability to BD.