Dysthymia is a chronic form of depression characterized by moods that are consistently low, but not as extreme as in other types of depression.

The exact cause of dysthymia is unknown. Although the symptoms are not as severe as those of other forms of depression, affected people struggle nearly every day with low self-esteem, despair, and hopelessness.

As with major depressive disorder, dysthymia occurs more frequently in women than in men and affects up to 5% of the general population. Dysthymia can occur alone or in conjunction with more severe depression or other mood or psychiatric disorder.

The main symptom of dysthymia is low, dark, or sad mood nearly every day for at least 2 years. Other symptoms can include:

• Poor appetite or overeating
• Insomnia or hypersomnia
• Low energy or fatigue
• Low self-esteem
• Poor concentration
• Feelings of hopelessness

Dysthymia is evaluated by taking a careful history of mood and other mental health symptoms over the past several months.

As with other forms of depression, there are a number of treatment options for people with dysthymia. Selective serotonin reuptake inhibitors such as fluoxetine (Prozac) are often used. Talk therapies, such as cognitive/behavioral therapy and interpersonal therapy, have also been shown to be effective.

Some evidence suggests the combination of medication and psychotherapy may result in the most improvement.

By definition, dysthymia is a chronic condition lasting many years. Though some people completely recover, others continue to have some symptoms despite treatment. Maintenance medication and therapy may be required.

Antidepressant drugs have a number of side effects that can complicate treatment. For example, selective serotonin reuptake inhibitors may cause stomach upset, mild insomnia, and reduced sex drive. However, untreated dysthymia can progress into a major depressive episode, a phenomenon known as "double depression."

Call for an appointment with your health care provider if you suffer from a persistently depressed mood.