Seasonal Affective Disorder – Identification and Treatment


David Prescott, PhD - Acadia Hospital
Healthy Living - January 12, 2016

With the Holidays Over, Are you Left Feeling Blue? With the holiday season over, for many people life begins to return to a more normal pace and routine. If, however, you find yourself feeling sad, tired, hopeless, or irritable, there is a chance that seasonal affective disorder may be the cause. A few days of feeling down or discouraged is probably no cause for alarm, but continuing to feel down for two or more weeks is a potential reason for concern.
Seasonal Depression Impacts Many People:  People who live in areas where daylight hours in winter are extremely short are more likely to be impacted by seasonal affective disorder, or seasonal depression.  According to the American Psychiatric Association, 10-20% of people in America feel more depressed with the onset of winter. A true diagnosis of seasonal affective disorder is less common, with estimates ranging from around 1% to 10% of the population during the winter, partly depending on the latitude at which you live.
Seasonal Depression, Lack of Sunlight, and the Body’s Internal Clock:   For some people, the onset of depression is clearly linked to shorter days and less sunlight.  By mid-January, Mainers have experienced over three months where there is more darkness than daylight each day. Researchers think that darkness is one of the signs the body uses to produce melatonin and other neurochemicals, which help induce sleep. Exposure to extended darkness may alter the body’s natural clock, leading to decreased energy and perhaps seasonal depression.
Does Treatment Work or Do We Just Have to Wait for Longer Hours of Daylight? It may be tempting to think that a person with Seasonal Affective Disorder simply has to wait for daylight hours to increase before they feel less depressed. However, treatments for Seasonal Depression are highly effective, with around 70% if people with SAD experiencing improvement with treatment. Treatments options include:
  • Light Therapy:  Light therapy (i.e., daily exposure to bright artificial light during the symptomatic months) is supported by research as an effective treatment for seasonal affective disorder. Clinical practice guidelines for SAD recommend daily use of light therapy each year from onset of the first symptom until the time in the spring when SAD symptoms would naturally resolve on their own. High intensity lights (2500 - 10,000 Lux) are important.
  • Cognitive-Behavioral Therapy:   Cognitive-behavioral therapy (CBT) is a type of psychotherapy that teaches clients to challenge unhelpful patterns of thinking and to engage in behaviors which counteract depression.   It is often helpful, in terms of reducing depression, to overcome the tendency to ‘hibernate’ during winter months, but to purposefully engage in activities every day. 
  • Get a thorough medical evaluation:  Sometimes depression can be caused by another medical problem, like abnormal thyroid activity. If you are more depressed and haven’t seen your primary care doctor, calling for a visit may be an important first step.
  • Exercise: The benefits of exercise for treating depression continue to accumulate.  As with other forms of depression, seasonal affective disorder is often well controlled through regular exercise. 
  • Medication:  Some anti-depressant medications, such as Wellbutrin XL, have been FDA approved for treatment of seasonal affective disorder. Your psychiatrist or primary care doctor can discuss a range of medical treatment options. 
Where can I get more information?  Here are some web links to learn more!
American Psychological Association:  or
American Psychiatric Association: