Examining the Impact of Daily Life Events on Mood in Bipolar I Disorder

Reward sensitivity and social rhythm theory have posited that individuals with bipolar I disorder (BD) may be more susceptible to mood changes following daily positive and negative (or stressful) events. However, research findings have been mixed regarding the specific impacts that these events have on mood and symptoms, and whether changes may persist over time, thus conveying for relapse. Further, it remains unclear whether these events may be associated with other behavioral changes, such as smartphone use. Thirty-two individuals (N = 18 individuals with euthymic bipolar I disorder and N = 14) demographically-matched healthy controls completed a survey via smartphone about their mood and the occurrence of positive and negative events three times per day for 21 days. Participants also installed a custom keyboard called BiAffect, which passively and unobtrusively measures smartphone keyboard typing patterns that are believed to be associated with psychomotor processing. Results showed that in general, positive events were associated with higher positive mood and negative events were associated with higher negative mood. Further, individuals with BD, when a positive event occurred, showed higher positive mood than HC, which persisted to the next timepoint. Similarly, when a negative event occurred, individuals with BD showed a larger increase in negative mood than HC, but this did not persist at the next timepoint. Neither positive nor negative events were significantly associated with typing speed. Overall, daily events differentially affect mood in BD, and this persistence over time may convey risk for future mood episodes.