Feeling down during the winter? You may have SAD (seasonal affective disorder)

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Natalie Staats Reiss, Ph.D. is a licensed Psychologist in the state of Ohio (License #6083). She received her Ph.D. in Clinical Psychology from ...Read More

Where I live, it’s been cold and gray for several days. We haven’t seen the sun much lately. It’s enough to make you want to put on some warm flannel pajamas, crawl back into bed, and throw the covers over your head. Imagine feeling this way for several months without end. People with Seasonal Affective Disorder, or SAD, have a temporary form of Major Depression that tends to flare during the winter.

Despite what many people think, SAD isn’t a disorder that is separate or different from Depression. Technically speaking, the label is actually a specifier for a Major Depression diagnosis. A specifier allows clinicians to provide additional information about a particular person’s symptoms when they make a diagnosis. People with SAD experience depressive symptoms (e.g., low mood, a lack of energy, sleep and appetite changes, feelings of guilt and self-blame, and hopelessness) that usually begin in the fall, peak in the winter, and resolve in the spring. A person’s cycle of SAD symptoms is typically related to seasonal changes in the amount of available sunlight. As the number of daylight hours decreases in the fall and winter, SAD symptoms peak. The inverse is also true, as the amount of daylight increases across the spring and summer months, SAD decreases.


It is not entirely clear what causes SAD. Some research suggests that the disorder is due to abnormalities in a person’s circadian rhythms. A circadian rhythm is a fluctuation in body, behavioral, and biochemical processes that is pegged to the 24-hour cycle of day and night. For example, our sleep/wake cycle, body temperature regulation, and a host of other functions all run on a circadian rhythm.

The "master clock" that drives circadian rhythms in mammals is located in the brain, in the suprachiasmatic nucleus (SCN, a group of cells located in the hypothalamus). The SCN synchronizes a group of other internal clocks that reside all over the body (e.g., in the heart, liver, etc.). Every 24 hours, the master clock tells our genes to turn on and off in a complicated set of patterns, which drives our other internal clocks.

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The SCN itself responds to light changes during the day, transmitting information that it has collected from the eye (the retina) to the pineal gland, a pea-shaped structure also located in the brain. The pineal gland is in charge of secreting the hormone melatonin, which seems to help our bodies know when to fall asleep and when to wake up. Melatonin levels are highest prior to bedtime and decrease during the day. During the low-light months of fall and winter, people with SAD seem to produce abnormally high levels of melatonin.

People with SAD have several different treatment options. Light therapy sessions (using a specialized lamp or light box for specified periods of time), either at home or in an office, can suppress the brain’s production of melatonin, helping regulate the body’s circadian rhythms and reducing symptoms. If symptoms do not respond to light therapy, some individuals with SAD find success with the SSRI (selective serotonin reuptake inhibitor) antidepressants fluoxetine (Prozac), sertraline (Zoloft), or paroxetine (Paxil). Some people may also respond to Cognitive Behavioral forms of psychotherapy, in which a therapist can help treat problematic thoughts and behaviors. There have not been extensive long-term, well-controlled investigations of which form of treatment is best for which kinds of people, so individuals with SAD may have to be patient and experiment before determining which treatment is most effective.

For more information on treating SAD, please see our article on Major Depression, by clicking here.

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