An overview of epidemiological studies on seasonal affective disorder

Abstract

The actuality of seasonal variation in mood has been documented thoroughly by both retrospective and prospective studies. In the general population, depressive symptoms peak in winter, and the most extreme form of this disposition, SAD, appears to be a relatively common disorder.

Seasonal Variations in Mood and Behaviour Associated with Gender, Annual Income and Education: The Hordaland Health Study

“…Nonetheless, considering the effect of month of completion discussed above, we can assume that most of the participants reporting seasonal changes experience most symptoms during winter months. In addition, summer-SAD has been shown to be far less prevalent than winter-SAD in northern latitudes [28].…”

Climate change and mental health: a causal pathways framework

“…This will increase the variability in climate-related mental health problems. For example, seasonal variation in mood has already been documented, with seasonal affective disorder, depressive symptoms, bulimia nervosa, anxiety disorders and other mental health problems usually peaking in the cold season when there is limited sunlight (Magnusson 2000). Where the climate warms, seasonal affective disorder may reduce somewhat, while it may be exacerbated in regions that receive fewer hours of sunlight.…”

Treatment duration with selective serotonin reuptake inhibitors among children and adolescents in Finland: a nationwide register study

“…However, all Finnish residents are entitled to receive at least 42% basic reimbursement for the costs of prescription drugs, including antidepressants, from the SII. The extent of cost-related nonadherence has not been widely studied [40][41][42][43]. It is possible that children and adolescents who initiated treatment during September to November had a milder form of depressive symptoms than those who initiated during the other seasons.…”