Preliminary evidence that misalignment between sleep and circadian timing alters risk‐taking preferences.

Summary: Decision‐making has been shown to suffer when circadian preference is misaligned with time of assessment; however, little is known about how misalignment between sleep timing and the central circadian clock impacts decision‐making. This study captured naturally occurring variation in circadian alignment (i.e., alignment of sleep–wake timing with the central circadian clock) to examine if greater misalignment predicts worse decision‐making. Over the course of 2 weeks, 32 late adolescent drinkers (aged 18–22 years; 61% female; 69% White) continuously wore actigraphs and completed two overnight in‐laboratory visits (Thursday and Sunday) in which both dim‐light melatonin onset (DLMO) and behavioural decision‐making (risk taking, framing, and strategic reasoning tasks) were assessed. Sleep–wake timing was assessed by actigraphic midsleep from the 2 nights prior to each in‐laboratory visit. Alignment was operationalised as the phase angle (interval) between average DLMO and average midsleep. Multilevel modelling was used to predict performance on decision‐making tasks from circadian alignment during each in‐laboratory visit; non‐linear associations were also examined. Shorter DLMO‐midsleep phase angle predicted greater risk‐taking under conditions of potential loss (B = −0.11, p = 0.06), but less risk‐taking under conditions of potential reward (B = 0.14, p = 0.03) in a curvilinear fashion. Misalignment did not predict outcomes in the framing and strategic reasoning tasks. Findings suggest that shorter alignment in timing of sleep with the central circadian clock (e.g., phase‐delayed misalignment) may impact risky decision‐making, further extending accumulating evidence that sleep/circadian factors are tied to risk‐taking. Future studies will need to replicate findings and experimentally probe whether manipulating alignment influences decision‐making. [ABSTRACT FROM AUTHOR]