This study examined the social zeitgeber theory, which suggests that affective symptoms are caused by life events disrupting vulnerable individuals' social and circadian rhythms. Undergraduate participants were selected based on a 2-phase screening process, including a semistructured diagnostic interview. The final sample consisted of 101 bipolar spectrum participants and 100 demographically matched normal controls. Participants who completed up to 3 follow-up visits, approximately every 4 months, as part of a longitudinal study were included in the current study. Life events did not predict social rhythm regularity and social rhythm regularity inconsistently predicted affective symptoms. However, life events, particularly social rhythm disruption (SRD) events, did predict depressive symptoms and episodes, and less consistently predicted hypo(manic) symptoms and episodes. Thus, the current study obtained mixed support for social zeitgeber theory.