Cognitive dysfunction and medical morbidity in elderly outpatients with bipolar disorder

OBJECTIVE: The authors investigated the differences in cognitive function, medical burden, and sociodemographic characteristics between elderly community-dwelling bipolar patients and age-matched and education-matched normal individuals. DESIGN: Case-control study. SETTING: Taipei Medical University Hospital, with 75 psychiatric beds, and Taipei City Psychiatric Center-a 612-bed psychiatric teaching hospital providing comprehensive psychiatric services. PARTICIPANTS: Eighty-two euthymic outpatients with bipolar I disorder aged older than 60 years received assessment for research purpose, 59 of whom were matched with one normal control for age and years of education. MEASUREMENTS: All subjects had measurements of cognitive function (Clock-drawing test and Mini-Mental State Examination [MMSE]). Medical morbidity and health condition were according to the medical records, results of free annual elderly health examination, and physical examination on research interviewing. RESULTS: Elderly bipolar patients were found to be more likely than the comparison group to have diabetes mellitus (27.1%), atopic diseases (20.3%), abnormal education-adjusted MMSE scores (32.2%), smoking habit (23.7%), and unfavorable social functioning (22%). Despite having noticeably higher heart rates, the bipolar patients' mean systolic blood pressure and prevalence of hypertension (44.1%) were significantly lower than those of the comparison group. CONCLUSIONS: Although community-dwelling elderly patients with bipolar disorder seem to be characterized by a greater likelihood of developing cognitive dysfunction and concurrent diabetes mellitus, there is no apparent increase in the morbidity of circulatory diseases, particularly less hypertension among those without previous dementia.