Prevalence of seasonal affective disorder among U.S. Army soldiers in Alaska.

OBJECTIVES

The goal of this study was to examine the prevalence of seasonal affective disorder among 1,116 active duty men and 191 active duty women stationed at an Army installation in Alaska.

METHOD

Prevalence estimates of seasonal affective disorder (SAD) were calculated in two different ways. The first was based on the "classic" criteria in which only January and February are regarded as the winter months. The second was based on the "arctic" criteria in which November and December are included as winter months.

RESULTS

Prevalence estimates of classic SAD were 5.2% for men and 8.9% for women. Prevalence estimates of arctic SAD were 6.5% for men and 13.1% for women. Subjects who met arctic criteria but not classic criteria for SAD self-reported significantly more current depression than those who met classic criteria.

CONCLUSION

The question of whether individuals meeting arctic criteria have a more severe form of SAD may be an area worth exploring.