Have you ever experienced a sensation of feeling blue or blah at this time of year? Now that the hours of sunlight are shorter, many people experience the “winter blues.” 

If you experience this every year, you might be suffering from a condition known as seasonal affective disorder, or SAD.

Seasonal affective disorder, also known as winter depression, is a mood disorder in which people who have normal mental health throughout most of the year experience depression symptoms in the winter or, less frequently, in the summer, spring or autumn, repeatedly, year after year. 

Until the 1980s, SAD was met with skepticism in the medical community, but research has confirmed the validity of this condition, and offered recommended treatment.

Between four and six percent of people in the U.S. suffer from significant SAD. Another 10 to 20 percent may experience a milder form of winter-onset SAD. It is more common in women and usually starts after age 20. Fortunately, the risk of SAD decreases as we get older. 

Winter-onset affective disorder is more common in northern regions such as ours, where the winter season is typically longer and harsher. Summer-onset SAD is less common and has different symptoms (see below). 

In both varieties, there are depression symptoms such as a feeling of hopelessness, and physical symptoms, such as headaches.

Symptoms of winter-onset SAD

• A change in appetite, especially an increased craving for sweet or starchy foods;
• Weight gain;
• A drop in energy level;
• Fatigue;
• A tendency to oversleep;
• Difficulty concentrating;
• Irritability and anxiety;
• Increased sensitivity to social rejection; and
• Avoidance of social situations and a loss of interest in the activities you used to enjoy.

Symptoms of summer-onset SAD

• A loss of appetite;
• Weight loss;
• Insomnia;
• Irritability and anxiety;
• Agitation; and
• Increased sex drive.

Diagnosis

There are specific diagnostic criteria that your doctor will use to determine if you have SAD. This is important so that medical insurance will pay for treatment. 

The criteria are:

1. You have been depressed during the same season and have gotten better when the seasons changed for at least two years in a row.
2. You have symptoms that often occur with SAD, such as being very hungry (especially craving carbohydrates), gaining weight and sleeping more than usual.
3. A close relative—a parent, brother or sister—has had SAD.

It is important to distinguish SAD from actual depression. There are many similarities. Symptoms of SAD tend to come back annually, but also resolve at about the same time every year. The changes in mood are not necessarily related to obvious things that would make a particular season stressful. 

Depression is not seasonal in nature and continues regardless of the time of the year. 

It is also important not to confuse SAD with the normal changes that we all experience in the winter when we tend to decrease activities and have lower levels of energy. Your physician, when he or she questions you about any of these symptoms, should be able to separate SAD from mild depression (known as dysthymia) and from major depression.

It is not clearly understood what causes this condition. There have been a number of studies measuring the levels of various brain chemicals, but the data has been inconclusive. 

There are also theories that the pineal gland of the brain is not stimulated by adequate amounts of light during the winter, leading to changes in brain chemistry.

Treatment

The type of treatment for seasonal affective disorder is guided by the severity of symptoms. There are many “cures” and supplements found in an internet search, but most are not substantiated by actual research. The following are the current recommendations:

Your doctor may recommend light therapy. There are two types of light therapy. In bright light treatment, you sit in front of a “light box” for half an hour or longer, usually in the morning. Units for purchase can be found via a web search. In dawn simulation, a dim light goes on in the morning while you sleep, and it gets brighter over time, like a sunrise.

Light therapy is effective and easy to use. You notice improvement within a week. But you need to stick with it and use it every day until the season changes. If not, your symptoms will return.

For more severe symptoms, the use of antidepressants might be needed. These medicines have been shown to improve mood, but need to be taken as directed and not stopped without a doctor’s supervision, just because you feel better. There are some side effects, so usually this type of medication is reserved for people with severe symptoms.

Psychological counseling could be offered to help you learn more about SAD and how to manage your symptoms.

Exercise is an important part of treatment. Being active during the daytime, especially first thing in the morning, could give you more energy and help you feel less depressed. Moderate exercise, such as walking, riding a stationary bike, or swimming, is a good way to get started.

Other proposed therapies include ionized air and the use of melatonin and Vitamin D.

In all cases, consult with your family doctor for evaluation and treatment if you feel that you could have seasonal affective disorder.