When it's more than 'winter blues'

Story highlights

  • About 5% of the population meets the criteria for seasonal affective disorder
  • Symptoms usually begin in the fall as the days shorten
  • Light boxes, antidepressants and psychotherapy can all help
  • Sufferers can also travel or, in extreme cases, move to sunnier climes

Dr. Charles Raison, CNNHealth's mental health expert, is an associate professor of psychiatry at the University of Arizona in Tucson.

(CNN)I grew up in a place where the sun shone every day from May through October. These sun-drenched days were the happiest times of my life.

But in winter a dense fog would often blanket my hometown for weeks at a time, leaving the world gray and featureless and leaving me down and dreary. These seasons were so definite, so unchanging, that I just came to believe that summer was happy and winter was sad.
No wonder, then, that I've always had a personal fascination with winter depression, known more commonly as seasonal affective disorder, or SAD.
    About 15% of the U.S. population experiences the problematic rhythmic change of the seasons. For these individuals, time itself is a stressor, and winter is often a season of despair.
    Most of these people who find the season a downer are able to power through the gray days and get by. But about 5% of the population becomes so impaired every winter that they meet the criteria for SAD.

    Symptoms

    Although everyone is a little different when it comes to how they experience depression, SAD tends to follow a remarkably stereotyped pattern.
    Symptoms usually start in the fall as the days shorten. Interestingly, for most people feeling depressed is not what comes first. Rather, people tend to become tired, to sleep more and to eat more -- especially carbohydrates -- and to gain weight as a result.
    They have increasing difficulty getting up in the morning and remaining interested in the things around them. Their ability to remember things and to concentrate diminishes. Only as winter bears down in earnest do sadness, despair and other classic emotional symptoms of depression take hold.
    Then, as the days lengthen and spring approaches, the symptoms began to evaporate in reverse order, with sadness/despair lifting first and sleep and appetite changes normalizing later.
    Many people with SAD experience normal moods from spring through fall, although some will actually become euphoric in spring, a condition known technically as "hypomania." This tendency for SAD sufferers to experience elevated moods during sunny ti