0950 Social Rhythm Regularity and Mood: Two Forms of Impulsivity with Differential Moderating Effects

Introduction Circadian rhythm dysregulation can elicit maladaptive consequences, including mental and emotional health problems. The social zeitgeber model theorizes that irregular social rhythms can disrupt biological rhythms, which negatively impacts mood. This relationship is particularly apparent among individuals diagnosed with bipolar spectrum disorders (BSD), such that social rhythm disrupting life events can trigger episode onset. Impulsivity, a core feature of BSD, has also been shown to differentially effect mood symptom pathophysiology (hypo/mania vs. depression). This study examined whether two forms of impulsivity moderated the association between social rhythm regularity (SRR) and mood symptoms (hypo/mania vs. depression) in individuals at low-risk, high-risk, and diagnosed with BSD. Methods Adolescents and young adults (n = 490) were recruited based on levels of trait reward sensitivity and diagnostic interviews. For this study, participants completed a self-report measure of attentional, motor, and non-planning impulsivity (Barratt Impulsiveness Scale [BIS]), and a behavioral task of reward-related impulsivity (the Balloon Analog Risk Task [BART]). Participants also completed measures of SRR, depressive, and hypo/manic symptoms. Models were estimated with SRR as the focal predictor and impulsivity as the moderator. Significant interactions were probed using simple slopes analyses. Results Both forms of impulsivity moderated SRR - mood symptoms relationship. BIS score moderated the association between SRR and hypo/manic symptoms, and simple slopes analyses revealed that only those low in impulsivity exhibited a positive association between SRR and hypo/manic symptoms. This finding was not obtained for the BART. BART score moderated the association between SRR and depressive symptoms, and simple slopes analyses found that only those who scored low in impulsivity exhibited a negative association between SRR and depression. This finding was not obtained with the BIS. Conclusion Individuals with low levels of impulsivity were most vulnerable to the effects of SRR on mood, although the polarity of the mood (hypo/mania versus depression) differed based on the impulsivity measure used (BIS versus BART). It is not clear whether the difference is due to self-report vs. behavioral measurement or to the differing forms of impulsivity assessed by the BIS vs. BART. Support (if any) NIMH R01 MH77908 to Lauren B. Alloy