Sleep and physical activity in patients with newly diagnosed bipolar disorder in remission, their first-degree unaffected relatives and healthy controls

BACKGROUND: Sleep disturbances are a central feature in bipolar disorder (BD) that often persist in remission and seem to be present also in unaffected first-degree relatives (UR) of patients with BD, presenting a possible risk factor for later onset of BD. However, it is unknown if these disturbances are associated with unhealthy life-style as reflected in low levels of physical activity. We investigated sleep disturbances and physical activity levels in patients with newly diagnosed BD in full or partial remission, their UR and healthy controls (HC). METHODS: Sleep patterns and physical activity were compared in 227 patients with newly diagnosed BD, 76 UR and 148 HC. The Pittsburgh Sleep Quality Index (PSQI) and the International Physical Activity Questionnaire (IPAQ) were used to assess sleep disturbances and physical activity, respectively. RESULTS: In sex- and age-adjusted analyses, patients with BD exhibited more sleep disturbances and lower physical activity compared with UR and HC, respectively. Unaffected relatives reported significantly longer sleep latency and a non-significant trend towards more overall sleep disturbances compared with HC. CONCLUSIONS: Sleep disturbances and less physical activity are present in patients with newly diagnosed BD in partial or full remission. Individuals at familiar risk of BD reported longer sleep latency and similar physical activity compared with HC. Further prospective studies are needed to clarify whether these discrete sleep disturbances act as risk factor for later onset of BD and whether increased physical activity in high-risk individuals may act as a protective factor against development of psychiatric illness.