Physical activity patterns across cognitive status groups in people with bipolar disorder in full or partial remission

Abstract Background Bipolar disorder is frequently characterized by reduced physical activity, increased sedentary behavior, and cognitive impairment, although the latter varies considerably across individuals. While physically active lifestyles are associated with better cognitive functioning in the general population, it remains unclear whether a similar relationship exists in bipolar disorder. This study explores physical activity patterns in bipolar disorder and assesses the association between cognitive status groups and self-reported and objectively measured physical activity. Methods Cross-sectional data were available from 79 participants with bipolar disorder in full or partial remission. Physical activity patterns were assessed using retrospectively self-reported physical activity, Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN), and accelerometer-measured physical activity over a 10-day period. Cognitive function was assessed with a self-administered Internet-based test platform. Participants were divided into 2 groups based on cognitive performance z-scores. Participants were classified as cognitively normal (0-1 test score at least 1 SD below the normative mean or cognitively impaired ( $$\ge 2$$ test scores at least 1 SD below the normative mean). Results The recommended levels of 150 minutes accelerometer-measured physical activity of moderate-to-vigorous intensity in bouts of at least 10 minutes were reached by 43 % of the participants. Participants in the cognitively normal group (n=49) had higher overall mean acceleration than those with cognitive impairment (n=30) (mean difference = 3.6 mg/day, 95% CI [0.4, 6.8]; t(77) = 2.22, p = 0.029). Time in moderate-to-vigorous physical activity levels or self-reported measures did not differ by cognitive status groups. Conclusion Although significant, the strength of the association between normal cognitive function and higher levels of physical activity was small. These findings suggest that accelerometer-derived measures may capture aspects of daily movement patterns that could be relevant to cognitive status groups, but longitudinal studies are needed to clarify their direction and clinical significance.