Seasonal affective disorder

Last reviewed: 23 Aug 2023
Last updated: 30 Jun 2022



History and exam

Key diagnostic factors

  • ≥2-year period of seasonally related changes in mood
  • fall or winter depression
  • spring or summer symptom remission
  • atypical depressive symptoms
  • vegetative depressive symptoms
  • spring or summer manic or hypomanic symptoms
  • spring or summer depression
  • manic/hypomanic symptoms
More key diagnostic factors

Other diagnostic factors

  • somatic symptoms
  • behavioral withdrawal
  • functional impairments
  • excessive alcohol use
  • tachycardia
  • increased systolic blood pressure
  • restlessness
Other diagnostic factors

Risk factors

  • exposure to diminished light during winter and increased light during summer
  • residing at a northern latitude
  • family history of seasonal affective disorder (SAD)
  • female sex
  • age 20 to 30 years
  • psychological factors (e.g., high neuroticism)
  • psychiatric comorbidity (e.g., anxiety, ADHD, premenstrual dysphoric disorders)
  • alcohol use
More risk factors

Diagnostic investigations

1st investigations to order

  • clinical exam
More 1st investigations to order

Investigations to consider

  • blood metabolic panel
  • serum thyroid-stimulating hormone
  • toxicology screen (urine and blood)
More investigations to consider

Treatment algorithm


subsyndromal SAD

SAD with recurrent, unipolar depressive disorder

SAD with bipolar mood disorder


prevention of SAD with unipolar mood disorder

prevention of SAD with bipolar mood disorder



Craig N. Sawchuk, PhD
Craig N. Sawchuk

Associate Professor

Co-Chair, Division of Integrated Behavioral Health

Department of Psychiatry and Psychology

Mayo Clinic




CNS declares that he has no competing interests.

Jason P. Veitengruber, MD
Jason P. Veitengruber

Assistant Professor

Department of Psychiatry and Behavioral Sciences

University of Washington School of Medicine




JPV declares that he has no competing interests.

William B. Leasure, MD

Clinical Instructor

Department of Psychiatry and Psychology

Mayo Clinic




WBL declares that he has no competing interests.

Peer reviewers

Stephen Lurie, MD, PhD

Director of Assessment

Office of Curriculum and Assessment

University of Rochester School of Medicine and Dentistry




SL declares that he has no competing interests.

Dietmar Winkler, MD

Department of Psychiatry and Psychotherapy

Medical University of Vienna




DW is an author of a number of references cited in this topic. DW declares that he has no competing interests.

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