Chronotype predicts positive affect rhythms measured by ecological momentary assessment

Abstract

Evening chronotype, a correlate of delayed circadian rhythms, is associated with depression. Altered positive affect (PA) rhythms may mediate the association between evening chronotype and depression severity. Consequently, a better understanding of the relationship between chronotype and PA may aid in understanding the etiology of depression. Recent studies have found that individuals with evening chronotype show delayed and blunted PA rhythms, although these studies are relatively limited in sample size, representativeness, and number of daily affect measures. Further, published studies have not included how sleep timing changes on workday and non-workdays, or social jet lag (SJL), may contribute to the chronotype-PA rhythm link. Healthy non-depressed adults (n = 408) completed self-report affect and chronotype questionnaires. Subsequently, positive and negative affect were measured hourly while awake for at least two workdays and one non-workday by ecological momentary assessment (EMA). Sleep variables were collected via actigraphy and compared across chronotype groups. A cosinor variant of multilevel modeling was used to model individual and chronotype group rhythms and to calculate two variables, (1) amplitude of positive affect, or the absolute amount of daily variation from peak to trough during one period of the rhythm, and (2) acrophase, or the time at which the peak amplitude of affect rhythms occurred. On workdays, individuals with evening chronotype had significantly lower PA amplitudes and later workday acrophase times than their morning type counterparts. In contrast to predictions, SJL was not found to be a mediator in the relationship between chronotype and PA rhythms. The association of chronotype and PA rhythms in healthy adults may suggest the importance of daily measurement of PA in depressed individuals and would be consistent with the hypothesis that evening chronotype may create vulnerability to depression via delayed and blunted PA rhythms.

Future Directions for Understanding Adolescent Bipolar Spectrum Disorders: A Reward Hypersensitivity Perspective

“…Reward system activation may be partly influenced by SCN timing information (e.g., Murray et al, 2009;Sleipness et al, 2007) and by SRD events that alter circadian rhythms. Consistent with this idea, studies show circadian influences on reward motivation in animals (Murray et al, 2009) and selfreported positive affect in humans (e.g., Miller et al, 2015;Murray et al, 2009), and there are time-of-day effects on cortico-striatal reward responsiveness in humans (e.g., Byrne et al, 2017;Hasler et al, 2014).…”

Trait positive and negative emotionality differentially associate with diurnal cortisol activity

“…At the same time, structural models of psychopathology suggest that depression is differentiated from other affective disorders by its association with low positive affect (Brown et al, 1998), which would, in turn, tend to reconcile our findings with reported evidence linking depression with HPA activity. Alternatively, like cortisol, positive (but not negative) affect has a diurnal pattern, raising the possibility that diurnal variation in PA may be entrained to diurnal variation in cortisol (Miller et al, 2015). …”

Eveningness among late adolescent males predicts neural reactivity to reward and alcohol dependence 2 years later

“…In both adolescent and young adult samples, evening-types (or late circadian preferences) score higher on measures tapping a range of reward-related constructs, such as impulsivity (4, 5), impulsive sensation seeking (6), sensation and novelty seeking (7), and risky decision-making (8). Evening-types also show altered daily rhythms in positive affect, ostensibly a manifestation of the reward system (9, 10). A handful of neuroimaging studies suggest that later sleep timing is associated with altered neural response to reward, at least in adolescents (11, 12).…”