Seasonal Affective Disorder (Seasonal Pattern)

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Seasonal Affective Disorder (Seasonal Pattern)

Medically reviewed · Ratel Health editorial team · Sunday, 16 August 2026

A pattern of recurrent major depressive episodes that occur at a specific time of year, most commonly during fall and winter months.

Overview

Seasonal affective disorder refers to a seasonal pattern of major depressive episodes that regularly begin and end at particular times of year, most commonly with depressive episodes beginning in fall or winter and remitting in spring.

Signs and Symptoms

Symptoms can include low mood, low energy, increased sleep, carbohydrate cravings, and weight gain, following a consistent seasonal pattern over at least two years. Experiencing one or more of these symptoms does not necessarily mean that a person has this condition. Diagnosis requires an appropriate clinical evaluation.

Causes and Risk Factors

Reduced exposure to natural light during shorter days is thought to play a central role, affecting circadian rhythms and brain chemistry involved in mood regulation.

Diagnosis

A diagnosis should be made by a qualified healthcare professional following a comprehensive clinical assessment. Clinicians may use established diagnostic frameworks such as DSM-5-TR and/or ICD-11 as part of a comprehensive assessment.

Treatment

Treatment depends on the individual’s symptoms, clinical history, severity, age, co-occurring conditions, and other relevant factors.

Psychotherapy

Light therapy and cognitive behavioral therapy adapted for seasonal depression both have evidence supporting their use.

Medication

Certain antidepressant medications are FDA-approved for seasonal affective disorder, sometimes used preventively before the typical seasonal onset. Medication decisions should be made with a qualified prescribing healthcare professional. Do not start, stop, or change a prescribed medication based solely on information on this page.

Living With Seasonal Affective Disorder (Seasonal Pattern)

Light therapy, maintaining outdoor activity during daylight hours, and consistent sleep schedules can help manage symptoms.

When to Seek Professional Help

Professional evaluation may be appropriate if symptoms persist, worsen, cause significant distress, or interfere with work, school, or relationships.

Emergency Situations

If a person may be in immediate danger, is experiencing a medical or psychiatric emergency, or may harm themselves or another person, seek immediate assistance through appropriate local emergency services.

Outlook

Many individuals see significant improvement with light therapy and/or other standard depression treatments.

Related Conditions

Major Depressive Disorder

A mood disorder involving persistent sadness or loss of interest that interferes with daily life for at least two weeks.

Persistent Depressive Disorder

A chronic depressive condition involving a depressed mood that occurs for most of the day, for more days than not, for at least two years.

Medical Information Disclaimer

Ratel Health provides general educational information and does not provide medical diagnosis, treatment, or individualized medical advice. Information on this page is not a substitute for evaluation or care from a qualified healthcare professional. Do not use this information to diagnose yourself or another person, or to start, stop, or change treatment or medication without consulting an appropriately qualified healthcare professional.

References

  • American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR).
  • National Institute of Mental Health.
  • World Health Organization. International Classification of Diseases, 11th Revision.