Tests and diagnosis

By Mayo Clinic Staff

To help diagnose seasonal affective disorder, your doctor or mental health provider will do a thorough evaluation, which generally includes:

  • Detailed questions. Your doctor or mental health provider will ask about your mood and seasonal changes in your thoughts and behavior. He or she may also ask questions about your sleeping and eating patterns, relationships, job, or other questions about your life. You may be asked to answer questions on a psychological questionnaire.
  • Physical exam. Your doctor or mental health provider may do a physical examination to check for any underlying physical issues that could be linked to your depression.
  • Medical tests. There's no medical test for seasonal affective disorder, but if your doctor suspects a physical condition may be causing or worsening your depression, you may need blood tests or other tests to rule out an underlying problem.

Seasonal affective disorder is considered a subtype of depression or bipolar disorder. Even with a thorough evaluation, it can sometimes be difficult for your doctor or mental health provider to diagnose seasonal affective disorder because other types of depression or other mental health conditions can cause similar symptoms.

To be diagnosed with seasonal affective disorder, you must meet criteria spelled out in the Diagnostic and Statistical Manual of Mental Disorders (DSM). This manual is published by the American Psychiatric Association and is used by mental health professionals to diagnose mental conditions and by insurance companies to reimburse for treatment.

The following criteria must be met for a diagnosis of seasonal affective disorder:

  • You've experienced depression and other symptoms for at least two consecutive years, during the same season every year.
  • The periods of depression have been followed by periods without depression.
  • There are no other explanations for the changes in your mood or behavior.
Sep. 22, 2011