Paul Macom

Seasonal Affective Disorder (SAD) is a type of winter depression that affects an millions of people, to one degree or another, every winter between September and April, in particular during December, January and February.

It is caused by a biochemical imbalance in the hypothalamus due to the shortening of daylight hours and lack of sunlight in winter. As seasons change, there is a shift in our "biological internal clocks" or circadian rhythm, due partly to changes in sunlight patterns. This can cause our biological clocks to be out of "step" with our daily schedules. The most difficult months for SAD sufferers are January and February, and younger persons and women are at higher risk. SAD may begin at any age but the main age of onset is between 18 and 30 years.

Melatonin, a sleep-related hormone has been linked to SAD. This hormone, which may cause symptoms of depression, is produced at increased levels in the dark. Therefore, when the days are shorter and darker the production of this hormone increases.

Symptoms may include the following:

  • Sleep problems: Usually desire to oversleep and difficulty staying awake but, in some cases, disturbed sleep and early morning wakening.
  • Lethargy: Feeling of fatigue and inability to carry out normal routine.
  • Overeating: Craving for carbohydrates and sweet foods.
  • Depression: Feelings of misery, guilt and loss of self-esteem, sometimes hopelessness, despair, and apathy.
  • Social problems: Irritability and desire to avoid social contact.
  • Anxiety: Tension and inability to tolerate stress.
  • Loss of libido Decreased interest in sex and physical contact.

Most sufferers show signs of a weakened immune, system during the winter, and are more vulnerable to infections and other illnesses.

Traditional antidepressant drugs such as tricyclics are not usually helpful for SAD. The non-sedative SSRI drugs such as sertraline (Lustral), paroxetine (Seroxat) and fluoxetine (Prozac) are effective in alleviating the depressive symptoms of SAD and combine well with light therapy.

Psychotherapy or counselling which helps the sufferer to relax, accept their illness and cope with its limitations are extremely useful.

Phototherapy or bright light therapy has been shown to suppress the brainís secretion of melatonin. Although, there have been no research findings to definitely link this therapy with an antidepressant effect, many people respond to this treatment. Light therapy has been proven effective in up to 85 per cent of diagnosed cases. That is, exposure, for up to four hours per day (average 1-2 hours) to very bright light, at least ten times the intensity of ordinary domestic lighting. Light treatment should be used daily in winter starting in early autumn when the first symptoms appear.

Treatment is usually effective within three or four days and the effect continues provided it is used every day. Tinted lenses, or anything that blocks the light to the retina of the eye, should not be worn.

No one should attempt any type of treatment, including phototherapy, without consulting a physician first.