Seasonal Affective Disorder (SAD), a type of depression that comes and goes with the seasons, typically starts in the late fall and early winter and goes away during the spring and summer. Depressive episodes linked to the summer can occur, but are much less common than winter episodes of SAD. To be diagnosed with SAD, people must meet full criteria for major depression coinciding with specific seasons for at least 2 years. Some of the symptoms of the winter pattern of SAD include having low energy, overeating, craving carbohydrates, and social withdrawal. Light therapy has become a standard treatment of SAD, and antidepressants have also been shown to improve SAD symptoms.
Some people turn to complementary health approaches to prevent SAD, including St. John’s wort, melatonin, and vitamin D. This issue of the digest provides the summary of current research for these modalities.
Modality and Summary of Current Evidence
There is some evidence that light therapy may be useful as a preventive treatment for people with a history of season affect disorder.
There is some evidence that cognitive behavioral therapy – SAD can be effective in reducing the recurrence and remissions of SAD and has been shown to be sustained at least between a first and second winter season.
There is limited evidence that St. John’s wort may improve some symptoms of SAD; however, the studies have been small.
There is some limited evidence (small trials involving few patients) that suggests melatonin improves sleep in some patients with SAD.
At present, vitamin D supplementation by itself is not considered an effective SAD treatment.