Differential Effects of CBT-I and Bright Light Therapy on Inhibitory Control and Risk-Taking Behavior in Youths with Comorbid Insomnia and Eveningness
Published in 40th Annual Meeting SLEEP 2026 - Baltimore, USA, 2026
Xin Xi Chen, Forrest Tin Wai Cheung, Xiao Li, Rachel Ngan Yin Chan, Joey Wing Yan Chan, Albert Martin Li, Colin Espie, Michael Gradisar, Yun Kwok Wing, Shirley Xin Li
Abstract
Introduction: Comorbid insomnia and eveningness are common in youth. Although cognitive behavioral therapy for insomnia (CBT-I) is well-established, it is unclear how CBT-I combined with circadian-targeted bright light therapy (BLT) impacts impulsivity-related cognitive processing in this population. This study examined effects of CBT-I with and without BLT on inhibitory control and risk-taking behavior using computerized neurocognitive tasks in youths with comorbid insomnia and eveningness.
Methods: A total of 146 participants (mean age = 19.9, SD = 3.2, 55.5% female) with DSM-5 insomnia disorder and eveningness (Reduced Morningness–Eveningness Questionnaire ≤ 11) were randomized into six weeks of CBT-I with BLT (CBT-I+BLT, N = 50), CBT-I with placebo light (CBT-I-BLT, N = 53), or waitlist group (N = 43). Inhibitory control and risk-taking behavior were assessed using Cue Go/No-Go (CGNG) task and Balloon Analogue Risk Task (BART). Linear mixed models were applied controlled for age, gender, depression and time of testing.
Results: In the CGNG task, significant Time×Group interactions were found for Cue and No-cue Reaction times (RTs) (Cue: F = 3.21, p = 0.044; No-cue: F = 3.50, p = 0.033), with only CBT-I-BLT group showing significant longer RTs from pre to post-treatment (cue: p = 0.001; No-cue: p = 0.003) without increased inhibition errors, suggesting enhanced response caution. In BART, a significant Time×Group interaction was observed for overall risky behavior attempts (All adjusted pumps: F = 3.25, p = 0.042). Both CBT-I+BLT (d = 0.59, p = 0.019) and CBT-I-BLT groups (d = 0.62, p = 0.025) had increased adjusted pumps relative to waitlist, suggesting heightened exploratory engagement. Notably, only CBT-I+BLT demonstrated a significant within-group increase in total earnings (d = 0.26; p = 0.046), suggesting adaptive risk-taking behavior. No other behavioral indices showed significant between-group differences.
Conclusion: CBT-I significantly enhanced response caution and adjunct BLT further improved adaptive risk-taking, reflecting changes in impulsivity-related cognitive processing in youths with insomnia and eveningness. Future studies could examine the mechanisms (e.g., reward processing) underlying these decision-making changes following CBT-I and bright light therapy.
Recommended citation: Chen, X. X., Cheung, F. T. W., Li, X., Chan, R. N. Y., Chan, J. W. Y., Li, A. M., Espie, C., Gradisar, M., Wing, Y. K., & Li, S. X. (2026). Differential Effects of CBT-I and Bright Light Therapy on Inhibitory Control and Risk-Taking Behavior in Youths with Comorbid Insomnia and Eveningness. Sleep, 49(Supplement_1), A199. https://doi.org/10.1093/sleep/zsag091.0446