Seasonal Affective Disorder (SAD) is a specific type of depression that occurs at the same time each year, typically in the late fall and winter.
Patterns & Symptoms
Symptoms of SAD usually begin in October or November, although they can start as early as August and as late as January. They tend to persist until March or April, with most affected reporting they do not feel completely back to normal until May.
Primary symptoms include:
While it is rare, it is possible for individuals to experience reverse SAD wherein they experience summer-onset of seasonal symptoms that typically involve anxiety, irritability, agitation, insomnia, poor appetite, and weight loss. Additionally, those who experience depression often report a worsening in symptoms during the winter months, and those with bipolar disorder can also experience seasonal changes in mood, with depressive episodes being more likely in the winter months.
Causes & Risk Factors
While the exact cause of SAD is unknown, it is widely thought to be due to lack of sunlight. Specifically, lack of sunlight is thought to disrupt the circadian rhythm, which regulates our internal clocks or sleep-wake cycles. Decreased sunlight may also disrupt levels of the hormone, melatonin, which affects sleep, as well as mood. Relatedly, it is thought that less sunlight can result in decreased levels of the neurotransmitter/brain chemical, serotonin, which affects mood.
SAD is more common in areas of the world in northern latitudes or those that are far from the equator. These are areas that have big changes in the amount of daylight when the seasons change. SAD is also more common in women, as well as in individuals who have family members with SAD, major depression, or even substance abuse problems.
The primary treatment methods are phototherapy, medication, and psychotherapy.
If you think that you or a loved one is experience SAD be sure to contact your health care provider to discuss your concerns, and always consult with your healthcare provider before implementing treatment options.
- Kara Meyer, Ph.D.
**The content of this site is for informational purposes only and is not intended to be and should not be used in place of the advice of your physician or other medical professional. This blog does not provide clinical advice, nor should its contents be considered clinical advice. Should you have any healthcare-related questions, please call or see your physician or other healthcare provider promptly.