When the days become shorter and the weather gets colder, many people experience sadness, fatigue, and a lack of interest in daily life. Those feelings could be nothing more than “holiday blues” or exhaustion.
But more severe, persistent depression that comes and goes with the seasons may be a medical condition known as seasonal affective disorder (SAD). Medical experts recommend learning how to spot the signs of SAD and getting help if you think you have the condition.
Psychiatrists classify SAD as a form of depression with a recurrent seasonal pattern, with symptoms lasting 4-5 months per year or longer. There are two kinds of SAD. Winter-pattern SAD starts in the late fall or early winter and resolves during the spring and summer. Other people may experience depressive episodes during the spring and summer months, although summer-pattern SAD is less common.
SAD symptoms may match those caused by major depression, but not every person with SAD will experience all of the symptoms listed below. Symptoms of major depression may include:
- Feeling depressed on most days
- Losing interest in activities you once enjoyed
- Changes in appetite or weight
- Difficulty falling or staying asleep
- Low energy
- Feeling hopeless or worthless
- Difficulty concentrating
- Frequent thoughts of death or suicide
For winter-pattern SAD, additional specific symptoms may include:
- Overeating, with a craving for carbohydrates
- Weight gain
- Social withdrawal (feeling like you are hibernating)
Causes and Risks
Matthew Macaluso, DO, clinical director of UAB Medicine’s Depression and Suicide Center, says the exact causes of SAD are not known, but extensive research shows certain risk patterns.
“If you have a pre-existing psychiatric illness, such as anxiety or substance abuse, then you may be at greater risk for SAD,” Dr. Macaluso says. “Age and family medical history may increase your risk as well. People living in a northern geographic region, where winter brings short days with very little sunlight, have a greater risk of developing SAD than people who see more sunlight.”
Dr. Macaluso is referring to the way researchers believe sunlight affects sleep cycles and brain chemistry. Here’s what is known:
- Reduced levels of sunlight may disrupt the body’s internal clock (circadian rhythm), which regulates sleep and alertness. A shift in circadian rhythm causes a sense of being out of step with one’s normal routine, which may lead to depression.
- Reduced sunlight can cause a drop in serotonin, a brain chemical that affects mood. Vitamin D, which the body produces when exposed to sunlight, is believed to promote serotonin activity.
- Other findings suggest that people with SAD produce too much melatonin, a hormone involved in maintaining the normal sleep-wake cycle. Overproduction of melatonin can increase sleepiness.
Dr. Macaluso says people experiencing symptoms related to SAD should track their mood and habits.
“Transient mood changes and temporarily feeling down can be normal responses to typical holiday stress,“ Dr. Macaluso says. “But if you feel down for many days and can’t get motivated to do activities you normally enjoy, don’t write that off as ‘the winter blues.’ If your sleep patterns and appetite have changed, or if you feel hopeless, think about suicide, or find yourself using alcohol or drugs to cope, then it’s time to see a doctor. Treatment is available.”
Treatment options include:
- Medication. Some people with SAD benefit from antidepressant treatment. Your doctor may want you to start this medication before your symptoms usually begin each year. Your doctor also may recommend that you continue medication even after your symptoms improve.
- Light therapy. Also called phototherapy, it involves spending 30 minutes per day in front of a specially designed lamp. Light therapy mimics natural sunlight and appears to cause a change in brain chemicals that affect mood.
- Psychotherapy. Psychotherapy, or talk therapy, can help you identify and change negative thoughts and behaviors that may be making you feel worse. You can also learn healthy ways to cope with SAD and manage stress.
Click here to learn more about psychiatric services at UAB Medicine and to schedule an appointment with a provider.