Cognitive decline in elderly bipolar disorder patients: a follow-up study

OBJECTIVE: Older individuals with bipolar disorder may exhibit greater cognitive decline over time compared to mentally healthy elderly individuals. We aimed to investigate neurocognitive performance in bipolar disorder over a period of two years.

METHODS: A comprehensive neuropsychological test battery was applied at baseline and two years later to 65 euthymic elderly outpatients with bipolar disorder (mean age = 68.35, range: 60-90 years) and to a demographically comparable sample of 42 healthy elderly controls. A general linear model was used to measure changes over time for the two groups. The impact of baseline illness characteristics on intra-individual change in neurocognitive performance within the bipolar group was studied by using logistic regression analysis.

RESULTS: At baseline and at follow up, bipolar disorder patients performed worse on all neurocognitive measures compared to the healthy elderly group. However, there was no significant group-by-time interaction between the bipolar disorder patients and the comparison group.

CONCLUSIONS: Although older bipolar disorder patients have worse cognitive function than normal controls, they did not have greater cognitive decline over a period of two years.