Seasonal Affective Disorder: Depression That Comes and Goes With the Seasons

What it is

Seasonal affective disorder (SAD) is a type of depression that comes and goes with the seasons. It usually starts in late fall and early winter and goes away in spring and summer. Some people have episodes that start in spring or summer, but that is much less common.

Symptoms

• sadness, and a gloomy outlook;
• feeling hopeless, worthless and irritable;
• losing interest or pleasure in things you used to enjoy;
• low energy;
• trouble sleeping, or oversleeping;
• carbohydrate cravings and weight gain;
• thoughts of death or suicide.

Who gets it

SAD is more common in women, young people, and people who live far from the equator. You're also more likely to have it if you or your family members have depression.

Causes

The exact causes are unknown. Researchers have found that people with SAD may have an imbalance of serotonin, a brain chemical that affects mood. Their bodies also make too much melatonin, a hormone that regulates sleep, and not enough vitamin D.

Treatment

• Light therapy is the main treatment. The idea is to replace the sunshine you miss in fall and winter: you sit in front of a light therapy box every morning for a daily dose of bright artificial light. Some people don't respond to light therapy alone.
• Antidepressants and talk therapy can reduce symptoms, alone or combined with light therapy.

If you're thinking about suicide, or worried about someone who is, call or text 988, the Suicide and Crisis Lifeline, any time.

Sources

Based on "Seasonal Affective Disorder," MedlinePlus, National Library of Medicine, drawing on the National Institute of Mental Health; a work of the United States government in the public domain.