Randomized double-blind placebo-controlled trial finds 68% of patients using bright white light therapy achieved remission of depression compared to 22% of patients who received the placebo light. Circadian-related genes, particularly NPAS2, have also been implicated in bipolar and major depressive disorder. For versions of 23andMe raw data that include the appropriate SNPs, this can be found in the comprehensive report at foundmyfitness.com/genetics. (Unfortunately, these SNPs are only available for the last version and not v5.)