Evening chronotype was associated with higher odds of insomnia
A meta-analysis linked evening preference with insomnia and higher symptom scores, but the observational evidence cannot establish that chronotype causes sleep problems.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
People classified as evening types had higher odds of insomnia and higher insomnia symptom scores than morning types. Intermediate types also showed associations in the same direction compared with morning types. These observational findings support a relationship between chronotype and insomnia, but do not establish causation or show that changing chronotype improves sleep.
The abstract does not report follow-up lengths, absolute insomnia rates or enough detail to assess differences between study populations. The included observational designs cannot establish that chronotype itself causes insomnia.
What researchers found
Insomnia
Evening versus morning chronotypes across the included studies; assessment periods were not reported. The estimate compares odds, not absolute probabilities.
Chronotype was measured by questionnaire
Studies classified morning and evening preferences using the Morningness-Eveningness Questionnaire. The review examined both insomnia as a categorical outcome and symptom scores, finding associations for evening and intermediate types compared with morning types.
The estimate is an odds comparison
The pooled odds ratio describes a difference between chronotype groups. Without absolute insomnia rates, it does not tell a reader their personal chance of insomnia or provide an absolute increase in that chance.
The original publication
Association between insomnia symptoms and chronotype-A systematic review and meta-analysis.
Zhao Y, Chen H, Åkerstedt T et al.
Sleep Health · 2025
- PubMed ID
- 40781036
- Record checked
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