Merikangas KR, et al. - Authors analyzed 242 participants to assess the dynamic relationships among motor activity, energy, mood, and sleep—as tracked in real time with mobile monitoring technology—in people with a history of bipolar disorder/major depression. Among study participants, 54 had bipolar disorder, 91 had major depressive disorder, and 97 were control participants with no history of mood disorders. The investigators identified a unidirectional relationship between motor activity and subjective mood level. In addition, bidirectional associations were noted between motor activity and subjective energy level, as well as between motor activity and sleep duration. Overall, they concluded that interventions that target motor activity and energy may be more efficacious than current approaches that target depressed mood, and both active and passive tracking of multiple regulatory systems are important in developing therapeutic targets.