Seasonal affective disorder: More than feeling sad

Seasonal affective disorder, or SAD, is a form of clinical depression that happens certain months of the year. Symptoms typically start to appear in the fall and tend to worsen with winter. The reduced amount of sunlight affects the natural chemicals in your body that determine mood and energy levels.

Affective disorders are mood disorders that have an impactful change in emotions and affect. Affective disorders significantly affect feelings and responses to emotions. SAD is not simply a case of the winter blues, a condition that is more mild and common. SAD symptoms are severe enough to make it difficult to function in social, work and home environments.

How does SAD differ from other types of depression?

SAD has a seasonal pattern to it, with recurring episodes happening more predictably during certain seasons of the year — most commonly during the winter months. SAD can have a predictable pattern to the depression, which is helpful for management of the disorder.

The criteria for diagnosing SAD are similar to diagnosing major depression, with the seasonal pattern as a key indicator.

Who is most at risk for experiencing symptoms of SAD?

People who live in the northern half of the U. S., where daylight hours are shorter and there is less sunlight, are more at risk for SAD. It's estimated that about 1 in 20 people in the northern half of the U.S. could have symptoms suggestive of SAD.

While a person is not born with SAD, it's believed to run in families. It's more common in women, as are all depressive disorders.

What symptoms indicate seasonal affective disorder?

On average, SAD will last about five months of the year. Typically, symptoms will develop in October, worsen around the end of daylight saving time, followed by a more drastic decline in November. January and February tend to be the months with the most severe symptoms of depression.

Symptoms to watch for include:

• Persistently feeling down or sad
• Losing interest in things you would normally enjoy, such as hobbies and social activities
• Sleep disturbances, which could include hypersomnia (sleeping too much) or insomnia (difficulty falling asleep)
• Feeling persistently tired and fatigued, including feeling a loss of energy nearly every day of the affected months
• Difficulty concentrating
• Feelings of worthlessness
• Weight changes, including weight gain or weight loss
• Suicidal ideation

Are there treatments available for SAD?

Bright light therapy is considered an effective treatment for SAD. There is research to suggest around half of people who use a bright light box — in the way it is intended to be used — have good results with symptom reduction. It's important to meet with a health care provider familiar with bright light therapy to determine the type of device needed to be effective, how to properly set it up and the length of time required in front of a light box.

Generally, the light box should provide an exposure of 10,000 lux of light and admit as little UV light as possible. Using the light box within the first hour of waking up in the morning for 20–30 minutes is the typical recommendation.

Medications, such as an antidepressant, prescribed by a health care provider can be an effective treatment option.

Physical activity also can help manage depressive symptoms. Research has shown that exercising at least three days a week for 20 minutes has similar effectiveness to taking an antidepressant. Exercising outdoors during daylight hours boosts the effectiveness of the activity.

Cognitive behavioral therapy, or CBT, is an effective treatment for SAD and clinical depression. CBT helps people learn how to manage their symptoms of depression or reduce the severity of the symptoms. Talk with your primary care provider about CBT and how to find a provider skilled at delivering CBT for depression or anxiety.

Because SAD is tied to the changing seasons, the onset can be predicted, which sets one up to better manage the symptoms. There are preventive measures that can be put in place and implemented before major depression develops.

Remember these tips:

• Make your environment bright.
  Open the window blinds and allow sunlight into your home. Sit near a window while at home or work.
• Get outside.
  If the weather allows, take a walk outside during the lunch hour when the sun is at its peak.
• Be physically active.
  Exercise helps relieve stress and anxiety. It is important to stay active during the winter months, as it is common to become inactive during the colder months.
• Be social.
  Decreased mood can lead to a behavior of stay home and isolate. Engaging with friends, staying in a routine, and getting active at home and outside of the home are important activities.
• Take care of your body and mind.
  Eat regular, healthy meals. Avoid drugs and alcohol, which can make depression worse.

If you have a history of SAD, talk with your health care provider about a plan to better manage mood during the winter months.

Janice Schreier is a clinical therapist in Psychiatry & Psychology in La Crosse, Wisconsin.