Some depressive episodes line up with the seasons. The most common pattern is winter, with symptoms starting in late fall and resolving in spring. A smaller group has the opposite pattern. The clinical name is major depressive disorder with seasonal pattern, sometimes still called seasonal affective disorder (SAD).
Quick view
- About 1 to 5 percent of U.S. adults meet criteria for the seasonal pattern, with rates rising at higher latitudes (Rosen et al., Psychiatry Res, 1990).
- The winter pattern features increased sleep, appetite, and weight, the opposite of melancholic depression.
- Bright light therapy and CBT for SAD have the strongest non-medication evidence; antidepressants (especially bupropion) are also first-line.
- Diagnosis requires a recurrent pattern: episodes that start and end at the same time of year for at least two consecutive years, with no nonseasonal episodes in between.
DSM-5-TR diagnostic criteria
"With seasonal pattern" is a specifier added to a diagnosis of major depressive disorder, recurrent. The DSM-5-TR requires a regular temporal relationship between the onset of major depressive episodes and a particular time of year (most often fall or winter), full remission (or a switch to mania or hypomania) at a characteristic time of year (most often spring), at least two such seasonal episodes in the past two years with no nonseasonal episodes during that period, and a lifetime pattern in which seasonal episodes substantially outnumber nonseasonal ones. The underlying episodes must still meet full criteria for major depressive disorder, which requires that there has never been a manic or hypomanic episode (otherwise the diagnosis is bipolar disorder with seasonal pattern).
Epidemiology
The reported prevalence varies with latitude and methodology. U.S. estimates range from about 1 percent in Florida to about 9 percent in Alaska, with most national surveys placing 12-month prevalence at 1 to 5 percent (Rosen et al., 1990; Magnusson, Acta Psychiatr Scand, 2000). Onset is typically in young adulthood, and women are affected at roughly two to three times the rate of men. A larger group has subsyndromal seasonal symptoms (the "winter blues") that affect functioning without meeting full criteria.
What it can look like
Increased sleep, increased appetite, cravings for carbohydrates, weight gain, and a strong pull to stay indoors. Low motivation. Withdrawal from social contact. Concentration that fades earlier in the day as daylight gets shorter. The summer pattern, when it occurs, is often the opposite, with reduced sleep, reduced appetite, agitation, and weight loss.
How it shows up in different people
- In adults, the winter pattern with hypersomnia and carbohydrate craving is most common.
- In adolescents, school performance often drops in late fall and recovers in spring; the pattern can be misread as motivation problems.
- In older adults, the seasonal component can be masked by other medical contributors and a careful longitudinal history helps.
- In women, the rate is roughly two to three times that in men, with perimenopausal years sometimes amplifying the pattern.
- In people who relocate to higher latitudes, a first seasonal episode can appear within the first year or two after the move.
Screening
The PHQ-9 detects the underlying depressive episode. The Seasonal Pattern Assessment Questionnaire (SPAQ) is a brief tool used to characterize the seasonal component. A clinician asks about the timing of past episodes to confirm the seasonal specifier.
When to seek same-day care
Suicidal thoughts with intent or a plan, inability to keep yourself safe, or new psychotic symptoms are reasons for same-day care. Call 988, call 911, or go to the nearest emergency department.
Treatment
Bright light therapy. A 10,000 lux light box used for 20 to 30 minutes within the first hour of waking has strong evidence for winter-pattern depression, with response rates of roughly 50 to 80 percent and onset of effect within one to two weeks (Golden et al., Am J Psychiatry, 2005). Side effects are typically mild (eye strain, headache, occasional irritability). People with bipolar disorder, retinal disease, or who take photosensitizing medications should consult a clinician before starting.
Medication. Bupropion XL has FDA approval for prevention of seasonal depressive episodes and is often started in the fall before symptoms begin. SSRIs are also effective. Treatment is typically continued through the symptomatic season and tapered as spring progresses, under a prescriber's care.
Therapy. Cognitive behavioral therapy adapted for SAD (CBT-SAD) has evidence comparable to light therapy and may have better long-term outcomes (Rohan et al., Am J Psychiatry, 2016). Daily anchors (morning outdoor light exposure, regular wake time, physical activity) support all of the above.
Sources
- American Psychiatric Association. DSM-5-TR. 2022.
- Golden RN, et al. The efficacy of light therapy in the treatment of mood disorders. Am J Psychiatry. 2005.
- Rohan KJ, et al. Outcomes one and two winters following CBT or light therapy for seasonal affective disorder. Am J Psychiatry. 2016.
- Rosen LN, et al. Prevalence of seasonal affective disorder at four latitudes. Psychiatry Res. 1990.
- National Institute of Mental Health. Seasonal affective disorder. Accessed 2026.
