Cognitive dysfunction and medical morbidity in elderly outpatients with bipolar disorder

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.

Case-control study.

Taipei Medical University Hospital, with 75 psychiatric beds, and Taipei City Psychiatric Center-a 612-bed psychiatric teaching hospital providing comprehensive psychiatric services.

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.

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.

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.

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.