Seasonal affective disorder, or SAD, is a type of depression that occurs the same time every year, typically in the fall when the days get shorter. SAD can sap your energy, make you moody, and disrupt your life. Many of us get the "winter blues," longing for summer days, but for others SAD can be a serious problem.
Winter-onset SAD (it can also occur in the summer months, but is much rarer) can cause feelings of depression, helplessness and anxiety. It can lower your energy level, change your sleep patterns, and cause difficulty concentrating. Many people with SAD withdraw socially and lose interest in activities they usually enjoy.
Eran Metzger, M.D., a psychiatrist at Hebrew SeniorLife, says SAD is caused by reduced levels of sunlight in the fall and winter months. This disrupts the body's internal clock (called circadian rhythm), which can lead to depression. Changes in sunlight can affect melatonin levels in the body, affecting sleep and mood, and decrease the amount of serotonin in the brain. Serotonin is a chemical that regulates our mood.
While both men and women can be affected by SAD, men typically have more-severe symptoms. People who live far from the equator, where daylight is decreased in the winter, and those with a family history of depression are at higher risk. Left untreated, SAD can lead to school and work problems, substance abuse, and, in more severe cases, suicidal thoughts and actions.
Dr. Metzger says it's normal to feel down on some days, but when the feeling persists and you have difficulty getting motivated, your sleep or appetite change dramatically, or you drink more to relax, then it's time to see your doctor.
If your doctor diagnoses you with SAD, he may suggest light therapy, which mimics outdoor light and appears to cause changes in the brain chemicals linked to mood. Or, if your symptoms are more severe, he may prescribe one of several antidepressant drugs. Psychotherapy, also called talk therapy, can help you identify and manage negative thoughts and behaviors that make you feel worse. Lifestyle changes such as getting outside more, making your house or office brighter, and exercising regularly can also help.
Dr. Metzger says you don't have to move closer to the equator to prevent seasonal affective disorder! Individuals who have responded to light therapy in the past may be able to prevent recurrences by re-starting light therapy in late August or early September, when the days start to shorten.