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Noninvasive, High-throughput Determination of Sleep Duration in Rodents

Published on: April 18, 2018

Bidirectional Mendelian randomization of childhood maltreatment and sleep-related phenotypes

Zheng Zhang1,2,3, Ying Liu1,2,3, Yuan Zhao1,2,3,4

  • 1Department of Sleep and Psychology, Chongqing Health Center for Women and Children, Chongqing, People's Republic of China.

European Journal of Psychotraumatology
|July 17, 2026
PubMed

Insights

Childhood maltreatment (CM) liability is genetically linked to increased daytime sleepiness, insomnia symptoms, and daytime napping. Reverse findings suggest shared genetic factors may influence both CM and sleep disturbances.

Area of Science:

  • Psychiatry
  • Sleep Medicine
  • Genetics

Background:

  • Childhood maltreatment (CM) is a known risk factor for sleep disturbances.
  • Observational studies are limited by confounding factors, shared familial genetics, and reverse causality.
  • Mendelian randomization (MR) offers a method to investigate genetic links between CM and sleep phenotypes.

Purpose of the Study:

  • To examine the bidirectional genetic relationship between composite childhood maltreatment (CM) liability and six sleep-related phenotypes using two-sample MR.
  • To differentiate genetic influences from environmental or familial factors in the CM-sleep disturbance association.

Main Methods:

  • Utilized two-sample Mendelian randomization (MR) analysis.
  • Employed genetic instruments for CM from a large GWAS meta-analysis of European ancestry.
  • Assessed six sleep phenotypes: chronotype, daytime sleepiness (DS), insomnia symptoms, sleep apnea (SA), daytime napping (DN), and sleep duration (SD).
  • Applied inverse-variance weighted MR as the primary method, with weighted median and MR-Egger sensitivity analyses.

Main Results:

  • Forward MR indicated that genetically proxied CM liability was associated with higher odds of daytime sleepiness (DS), insomnia symptoms, and increased daytime napping (DN).
  • No significant genetic association was found between CM liability and chronotype, sleep apnea (SA), or sleep duration (SD).
  • Reverse-direction MR suggested a genetic link between daytime napping (DN) and insomnia symptoms with CM liability.

Conclusions:

  • This study provides suggestive genetic evidence for a link between childhood maltreatment (CM) liability and specific sleep disturbances, including daytime sleepiness, insomnia symptoms, and daytime napping.
  • Bidirectional findings may indicate shared genetic liability, gene-environment correlations, or reporting biases rather than direct causal effects of sleep on CM.
  • Results should be interpreted cautiously due to modest effect sizes and sensitivity analyses supporting the findings.
Keywords:
Childhood maltreatmentMaltrato infantilMendelian randomizationaleatorización mendelianadaytime nappingfenotipos relacionados con el sueñoinsomnia symptomssiestas diurnassleep-related phenotypessíntomas de insomnio

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