Greater circadian misalignment predicts reduced REM sleep, which in turn predicts poorer extinction recall
In a randomized controlled trial of 42 healthy adults, greater circadian misalignment on Night 4 significantly predicted larger reductions in REM% and REM minutes. Reductions in REM minutes on Night 4 significantly predicted poorer extinction recall the following day, even after controlling for total sleep time and slow wave sleep.
This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.
Greater circadian misalignment predicts reduced REM sleep, which in turn predicts poorer extinction recall The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 44/100 (low).
The Claim
Greater circadian misalignment predicts reduced REM sleep, which in turn predicts poorer extinction recall
This conclusion is most relevant to: Healthy adults (mean age 24.89, SD 5.11).
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸A preliminary investigation of the relationship between rapid eye movement (REM) sleep and fear inhibition processes in the context of circadian misalignment. (Psychological trauma : theory, research, practice and policy, 2026) — In a randomized controlled trial of 42 healthy adults, greater circadian misalignment on Night 4 significantly predicted larger reductions in REM% and REM minutes. Reductions in REM minutes on Night 4 significantly predicted poorer extinction recall the following day, even after controlling for total sleep time and slow wave sleep.
How It Works
The proposed biological pathway:
- ▸Circadian misalignment leads to reduced REM sleep (both percentage and minutes)
- ▸Reduced REM minutes on Night 4
- ▸Poorer extinction recall the following day
- ▸Impaired fear inhibition may increase risk for trauma-related psychopathology
Who Might Benefit
Evidence fit by population:
- ▸Healthy adults (mean age 24.89, SD 5.11)
Recommended Dose
N/A
Limitations & Caveats
Important context when interpreting this evidence:
- ▸Small sample size (n=42) and preliminary nature of findings
- ▸Melatonin administration was not fully controlled for in the analysis of circadian misalignment effects
- ▸Only two consecutive phase advances may not fully represent real-world circadian disruption patterns
Frequently Asked Questions
What is the main finding of this study?▼
The study found that greater circadian misalignment leads to reduced REM sleep, and that reductions in REM minutes are associated with poorer extinction recall, a key process in fear inhibition.
How was circadian misalignment induced?▼
Circadian misalignment was induced by two consecutive 4-hour phase advances over four nights, with some participants receiving melatonin (3 mg) or placebo.
What was the sample size and population?▼
The study included 42 healthy adults with a mean age of 24.89 years (SD = 5.11).
What are the implications of this research?▼
The findings suggest that circadian misalignment, common in occupations with high trauma risk, may impair fear inhibition via reduced REM sleep, potentially increasing vulnerability to PTSD.
References
- 1.Vuong V, McGlashan EM, Birch S, Acheson D, Kavaliotis E, Courtney JA, Risbrough VB, Drummond SPA. “A preliminary investigation of the relationship between rapid eye movement (REM) sleep and fear inhibition processes in the context of circadian misalignment..” Psychological trauma : theory, research, practice and policy, 2026. PMID: 42658639 DOI: 10.1037/tra0002257