Assessment of Cognitive Performance in Bipolar Disorder Type I Patients and Their Unaffected Offspring

Patients with bipolar disorder type I (BP-I) often present with impairments in cognitive function. Offspring unaffected by the disorder can also present with cognitive dysfunction. The objective of this study was to compare the cognitive function of BP-I patients, their unaffected offspring (UO) and healthy control subjects (HC).

Verbal memory, working memory index, processing speed, attention, verbal and phonological fluency and executive function were evaluated through the application of a neuropsychological battery to three groups made up of BP-I patients that attended the Bipolar Disorder Outpatient Clinic of Clínica San Juan de Dios de Manizales [San Juan de Dios de Manizales Clinic] (n=30), UO (n=32) and control group (n=31). The UO group and the control group were matched by gender, age and level of education.

Major differences between the three groups were found in the measures of cognitive functions (except in semantic fluency). The HC group showed better cognitive performance in all the functions. Post-hoc analysis showed similar results in the cognitive performance between BP-I and UO except in verbal learning and executive function tasks where the results were better in UO. A better performance in the control group was found, compared to the UO group, in executive function, attention, working memory, and semantic fluency and phonological areas.

These results indicate that the offspring of patients with BP-I present with cognitive impairments without suffering from the disorder. This suggests that cognitive dysfunction presents without diagnosis and supports the hypothesis that it can correspond to a BP-I endophenotype.