Dr. David Lipschitz, columnist
Updated: December 14, 2013 6:09AM
Daylight savings has started. The fall foliage is in full splendor and everyone is looking forward to Thanksgiving and the holiday season. But as the days become shorter and bleaker, the prevalence of depression increases.
Approximately 10 percent of the population develops a condition called seasonal affective disorder or SAD that is characterized by symptoms of depression, including fatigue, weakness, a sense of worthlessness, withdrawal, less socialization, difficulty concentrating, and weight gain. A rather common symptom is increased appetite and an unexplained craving for carbohydrates and sugar. The condition is more common in women and tends to occur in families. SAD occurs more frequently in those diagnosed with clinical depression in the past and in those with bipolar disorder.
Less exposure to the sun as the days shorten is thought to cause SAD. Exposure to sun affects our biologic clock, which tells us when it’s time to get up and during the evening prepares us for sleep. Also referred to as a circadian rhythm, many hormones tend to increase in the early morning and decrease as evening and nighttime approaches or vice versa.
In regard to depression levels, melatonin appears to be the most important. This hormone, produced by the pineal gland, progressively increases in concentration a few hours before bedtime, reaching a peak in the early hours of the morning and then decreasing shortly before we waken. It reaches a low point in the early to late afternoon. Changes in the concentration of melatonin because of less exposure to sunlight appear to precipitate depression in susceptible individuals.
Another cardinal abnormality found in SAD is a decline in the concentration of serotonin in the brain. This chemical, also referred to as a neurotransmitter, has a major effect on mood, and reductions in its concentration in the brain are thought to be a major reason for many of the symptoms found in depressed patients.
It is quite difficult to differentiate SAD and depression from other causes. To make the diagnosis the following criteria must be met. Depression must have been present on at least two consecutive years during the fall and early winter. Recovery during the spring and summer should occur, and there should be no other reason to explain the presence of depression.
Although treatment with medications may be needed, the initial approach should be to correct the biologic clock by increased exposure to sunlight during the waking hours. For some, merely spending more time outdoors may prove effective, but for many, light or phototherapy may be needed. The principle of treatment is to spend as much time as possible during the day a few feet away from a specialized light therapy box whose bright light mimics sunlight. This tends to reduce melatonin and increase serotonin levels, which improve the biologic clock and relieve the symptoms of depression.
Another approach to treatment is referred to as “dawn stimulation”: Here a dim light goes on a short time before dawn and becomes progressively brighter, reaching a peak a short time before you are due to wake up. This creates the impression of a sunrise and positively affects the biologic clock.
It takes 1-2 weeks before the benefits of phototherapy become apparent. Most importantly, if beneficial, exposure to light must continue throughout winter to assure that symptoms do not recur.
Like any other cause of depression and depending on the severity of symptoms, treatment with an antidepressant may be needed. In most cases, these can be discontinued in the spring. Just as important is paying attention to your health. Eat right, exercise regularly, avoid being lonely and make sure that your house is bright and airy.
If depression is recurrent or if you have suffered episodes of depression in the past always consider psychotherapy. A qualified psychotherapist will prove invaluable in teaching how to better cope with the stresses of life and triggers that led to depression.
Sadly, we as a society always seem to lean towards being helped by a medication without paying attention to the many other factors that determine how well we deal with any illness. This particularly applies to our approach to depression, no matter the cause.
Dr. David Lipschitz is the author of the book “Breaking the Rules of Aging.”