Seasonal Affective Disorder

As the days grow shorter in the autumn, some people develop symptoms of seasonal affective disorder (SAD), a type of depression with a recurring seasonal pattern. Treatments that have been studied for SAD include antidepressant medication, psychotherapy, light therapy, and dietary supplements.

There’s evidence that antidepressant medication, cognitive behavioral therapy (a type of psychotherapy), and light therapy can all have beneficial effects on SAD symptoms.

The evidence is less favorable for dietary supplements. Although low levels of vitamin D have been found in some people with SAD, it’s unclear whether supplements of this vitamin can help relieve SAD symptoms. Very little research has been done on other dietary supplements, and none have clearly been shown to be helpful.