Molecular genetic overlap between posttraumatic stress disorder and sleep phenotypes

Area of Science:

• Psychiatry and Genetics
• Sleep Medicine
• Genomic Epidemiology

Background:

• Sleep disturbances are common in posttraumatic stress disorder (PTSD), exhibiting a bidirectional relationship.
• Both sleep phenotypes and PTSD have moderate heritability, suggesting a potential genetic overlap.
• Previous research has not extensively explored the genetic underpinnings connecting sleep and PTSD.

Purpose of the Study:

• To investigate the genetic correlations between various sleep phenotypes and PTSD.
• To leverage large-scale genome-wide association study (GWAS) data for PTSD and sleep traits.
• To explore potential shared genetic etiology between sleep disturbances and PTSD.

Main Methods:

• Utilized linkage disequilibrium score regression (LDSC) to estimate genetic correlations from GWAS summary statistics.
• Conducted Mendelian randomization (MR) analyses to investigate potential causal relationships.
• Analyzed GWAS data for PTSD and multiple sleep phenotypes (insomnia, sleep duration, daytime sleepiness, chronotype) from UK Biobank.

Main Results:

• Found significant, moderate genetic correlations between insomnia symptoms, oversleeping, undersleeping, and PTSD.
• Observed mixed results for continuous sleep duration and daytime sleepiness phenotypes.
• No significant genetic correlation was found between chronotype and PTSD; MR analyses did not support causal effects of sleep on PTSD.

Conclusions:

• Sleep phenotypes, especially insomnia and extreme sleep durations, share genetic factors with PTSD.
• Identified shared genetic etiology but did not establish causal relationships between sleep phenotypes and PTSD.
• Further research with larger sample sizes and advanced methods is needed to clarify directionality and causality.