Genetic proximity to diurnal preference, sleep timing, and risk of major depressive disorder.

The results of this Mendelian randomized study support a protective association between risk of MDD and early diurnal preference and provide contextualized estimates for objective sleep timing measures. Further investigation in the form of a randomized clinical trial may be warranted.

PMID: 34037671 DOI: 10.1001 / jamapsychiatry.2021.0959

Commentary.

It has been said that lifestyle rhythm is associated with a decreased risk of major depressive disorder (MDD), but the causality of this association is unknown. This study used Mendelian randomization to investigate genetically proximate morning diurnal preference and depression risk.

As a result, a total of 697,828 subjects were included, and it appears that genetically close early morning diurnal preference was associated with a 23% lower risk of depression, according to a study conducted by the Psychiatric Genomics Consortium (OR, 0.73 [95% CI, 0.54-1.00]; P = 0.05), this association was similar when the analysis was restricted to individuals with MDD as strictly defined by the MDD, but was not statistically significant when defined by hospital-based billing codes.