seasonal affective disorder
By Lisa Cuseo-Ott, Ph.D., January 2011
Winter is upon us in full swing. Gone are the festive lights and distractions of the holiday season. We are now left with shorter days and longer nights, which causes a state of depression for many individuals who suffer from Seasonal Affective Disorder (SAD).
SAD affects approximately 6% of Americans, who, during the winter months, can experience an increase in sluggishness, sleep, weight gain and feelings of depression. Although it is common for many people to feel somewhat "blue" after the holidays have passed, if this feeling persists with the above symptoms for at least two weeks, then it constitutes a mood disorder and requires treatment.
There is a higher prevalence of SAD in the northern latitudes, which supports the theory that SAD is related to seasonal changes in the environment. In particular, studies have found a correlation between the amount of light exposure and the occurrence of Seasonal Affective Disorder. In a small percentage of people, this light sensitivity occurs during the summer months, when these individuals become depressed during the longer days of sunlight. This suggests that SAD may stem from a problem adapting to the physical environment.
This begs the question, how do changes in light reaching our bodies affect our brain's ability to function? Light plays an important role in regulating our biorhythms. As it reaches the pineal gland in the middle of the brain, the hormone melatonin is secreted. Melatonin is the hormone that regulates the circadian rhythms in the body, thus affecting our sleep/wake cycle and other bodily functions. People who are susceptible to SAD seem to have a biologically-based problem regulating and adjusting their biorhythms or circadian rhythms to the change in seasons. Their brains cannot adjust as easily to the decrease in light during the day, which in turn creates less melatonin in the brain.
Consequently, phototherapy is one of the most effective treatments for SAD. This involves placing oneself in front of a "light box" for 30 minutes per day during the winter months. The "box" consists of a 10,000-lux diffused, white fluorescent light. By exposing the brain to a high concentration of artificial light, the pineal gland secretes more melatonin. There also appears to be an increase in serotonin, which is the neurotransmitter found to be low in people suffering from depression.
Research has found that the best form of treatment for SAD is a combination of phototherapy and Cognitive Behavioral Therapy (CBT). CBT challenges the negative cognitions and tendency to personalize experiences, which is often associated with depression. A therapist helps an individual with SAD focus on creating positive experiences during the winter months to compensate for their vulnerability to depression. As with many other psychological conditions, it is always helpful to practice good stress management by maintaining regular exercise and setting appropriate expectations for oneself and others. It is especially important for individuals with moderate levels of SAD to get outside approximately one hour each day - the perfect amount of time in which to take a walk!