Can Sleep Apnea Actually Change Your Personality?

A study of 233 adults found obstructive sleep apnea was linked to lower neuroticism and psychoticism scores, and genetic analysis suggested the sleep disorder may causally lower neuroticism.

Obstructive sleep apnea (OSA), a condition where breathing repeatedly stops and starts during sleep, is known to affect mood and daytime functioning, but its relationship to stable personality traits was less clear. Researchers led by Jia-Hui Liao studied 233 adults who underwent overnight sleep monitoring and completed standard personality assessments based on the Eysenck model, which measures extraversion, neuroticism, and psychoticism, along with classic temperament categories like melancholic, choleric, and sanguine. People with more severe OSA tended to score significantly lower on both neuroticism and psychoticism, and temperament profiles shifted from melancholic toward choleric or sanguine types as sleep apnea severity increased. To probe whether OSA might actually cause these differences rather than just correlate with them, the team also ran a Mendelian randomization analysis, a genetics-based method that uses naturally occurring genetic variation to test for causal effects. That analysis supported a causal link between OSA and reduced neuroticism specifically. The authors suggest sleep apnea management could benefit from including psychological screening. However, they caution that the effect sizes were modest, the sample was relatively small, and causal claims from Mendelian randomization in a single cohort should be interpreted carefully rather than treated as definitive.