A Longitudinal Study of the Relationship Among Cognition, Mood Symptoms, and Markers of Brain Health in Older Age Bipolar Disorder: Une étude longitudinale de la relation entre la cognition, les symptômes thymiques, et les marqueurs de la santé du cerveau en présence de troubles bipolaires du sujet âgé.

ObjectivesAn emerging literature has assessed cognition or imaging markers of brain health in in older age bipolar disorder (OABD). In this context, we conducted the first longitudinal study (to our knowledge) that assessed the relationship among cognition, mood symptoms, and imaging markers of brain health in OABD.Methods99 participants with OABD were enrolled, underwent baseline assessment, and were followed annually for up to 3 years. They completed comprehensive assessments that included evaluation of general medical status, vascular disease burden, mental status, cognitive performance. A subset of participants (n = 58) completed magnetic resonance imaging (MRI) at one or two time-points, yielding three measures of brain health: gray matter volume, fractional anisotropy (FA), and burden of white matter hyperintensities (WMH).ResultsGroup-based trajectory modelling (GBTM) of overall cognitive performance revealed two groups: a group with higher cognitive performance (63 of 99, 63.6%) and a group with lower cognitive performance (36 of 99, 36.4%). GBTM also revealed two groups based on each of the three imaging markers of brain health. The higher cognitive performance group was associated with the groups with higher measure of total gray matter or higher FA. We found no relationship between the cognitive groups and level of mood symptoms during longitudinal follow-up or WMH burden.ConclusionsIn this first longitudinal study of cognition, mood symptoms, and markers of brain health in OABD, cognitive performance was related to brain health and not to mood symptoms over a follow-up of up to three years. Almost two-thirds of participants with OABD had cognitive performance comparable to older adults without OABD. Larger future studies will need to replicate and extend these findings.