Relationship between prior course of illness and neuropsychological functioning in patients with bipolar disorder

Background: This study investigated the relationship between prior course of illness and neuropsychological deficits in relatively high functioning outpatients with bipolar disorder. Method: Forty-nine bipolar I or II patients, in a relatively euthymic state during treatment with mood stabilizers, were administered neuropsychological tests that assessed a variety of functions, including verbal memory, sustained attention and vigilance, and intelligence. A detailed retrospective life chart was completed for each patient using the NIMH Life Chart Method(TM) to define variables reflecting duration and severity of illness, and frequency of episodes. Results: Stepwise multiple regression analyses show that several different measures of a more severe course of prior illness related to greater duration and a larger number of affective episodes and hospitalizations were associated with poorer performance on tests of abstraction, attention and memory. Conclusion: The results indicate that bipolar patients with a more severe prior course of illness and a greater number of affective episodes have more impaired neuropsychological functioning. The direction of causality and the pathophysiological mechanisms remain to be explored. (C) 1999 Elsevier Science B.V. All rights reserved.