Evening Exercise Reduces Depressive Symptoms in Bipolar Spectrum Disorder

Vigorous evening activity was associated with a greater reduction in subsequent depressive symptoms in patients diagnosed with bipolar spectrum disorders (BSD), according to study findings published in Depression & Anxiety.

Researchers conducted a baseline and 6-month follow-up survey using self-reported questionnaires that comprised 111 young adults (age range 18-27 years) identified as low BSD risk (moderate reward sensitivity [40th-60th percentile in both measures]), high BSD risk (high reward sensitivity [85th-99th percentile in both measures]), and BSD diagnosis who participated in a 20-day ecological momentary assessment (EMA) study. Wrist actigraphy counts measured physical activity as a percentage of time awake spent in light, moderate, and vigorous activity as well as percentage of morning hours and evening hours in each activity state.

Study participants were a subset of individuals enrolled in Project TEAM, a 2012 longitudinal study of BSDs in adolescents. Several years after initial enrollment in Project TEAM, they were invited to participate in the study, completing both the actigraphy and EMA study on sleep, mood, rhythms, and reward.

Survey questions concerning depressive symptoms were answered 3 times per day for 20 days. Reward sensitivity was measured with the BIS/BAS 20-item self-report questionnaire, which measured approach and avoidance tendencies, and with the SPSRQ 48-item self-report questionnaire, assessed specific rewards and punishments. Mood symptoms were determined with the Beck Depression Inventory-II self-report questionnaire, which measures depressive symptoms. Chronotype and sleep were measured with the Morningness-Eveningness 19-item self-report questionnaire gaging morning vs evening preference for daily activities.

Researchers found time spent in each activity state showed no between-group differences. Overall, participants were 13% sedentary, 13% engaged in vigorous activity, 34% in light activity, and 40% in moderate activity. There were no main effects caused by sedentary or vigorous activity on next-day depression. The group diagnosed with BSD showed increased time spent in vigorous activity associated with greater subsequent depressive symptom reduction. Specifically, increased evening but not morning vigorous activity was significantly associated with subsequent depressive symptom reduction for this group when controlled for chronotype.

Limitations of the study include the lack of formal exercise measurements, lack of generalizability to older individuals, a survey structure that may have failed to capture mood variability, and the fact that analysis did not account for bipolar subtype or medication status.

Study authors conclude, “[A]n increase in vigorous activity, specifically in the evening, was associated with a greater reduction in subsequent depressive symptoms. “Interventions targeting physical activity may be effective nonpharmacologic options for regulating inter‐episode mood disturbances in BSD.”