Persistent depressive disorder (dysthymia)

What is it?

Persistent depressive disorder (dysthymia) is a form of depression. It may be less severe than major depression, but — as the name suggests — it lasts longer. Many people with this type of depression describe having been depressed as long as they can remember, or they feel they are going in and out of depression all the time.

The symptoms of persistent depressive disorder are similar to those of major depression. In this disorder, the long duration is the key to the diagnosis, not the intensity of symptoms. As with major depression, mood may be low (or irritable in children and adolescents). An individual with persistent depressive disorder may feel less pleasure and a lack of energy. He or she may feel relatively unmotivated and disengaged from life. Appetite and weight can increase or decrease. The person may sleep too much or have trouble sleeping. Indecisiveness, pessimism and poor self-image may also be present.

Symptoms can grow into a full-blown episode of major depression. People with persistent depressive disorder have a greater-than-average chance of developing major depression.

While major depression often occurs in episodes, persistent depressive disorder is defined as more constant, lasting for years. The disorder sometimes starts in childhood. As a result, a person with persistent depressive disorder tends to believe that depression is part of his or her character, and so self-defining that he or she may not even think to talk about this depression with doctors, family members or friends.

Persistent depressive disorder, like major depression, tends to run in families. It is more common in women than in men, but in men it may be underdiagnosed because men are less likely to talk to their doctors about their mood. Some people with persistent depressive disorder have experienced a major loss in childhood, such as the death of a parent. Others describe being under chronic stress. But it is often hard to know whether people with the disorder are under more stress than other people or if the disorder causes them to perceive more stress than others do.

Symptoms

The main symptom of persistent depressive disorder is a long-lasting low or sad mood. Children and adolescents with persistent depressive disorder may be irritable. Other symptoms include:

• Increased or decreased appetite or weight
• Lack of sleep or sleeping too much
• Fatigue or low energy
• Low self-esteem
• Difficulty concentrating
• Indecisiveness
• Hopelessness or pessimism

Diagnosis

Many primary care doctors can recognize when one of their patients has some form of depression, which may lead to a referral to a mental health professional for a full evaluation. Clinicians diagnose the depression as persistent depressive disorder when an adult has had low mood, along with some of the other depressive symptoms, for two years or more. (In children, presistent depressive disorder may be diagnosed after one year of symptoms.)

It is not necessary to wait for two years before getting help! Someone who has symptoms for less than two years may still be treated for any persistent or distressing symptoms.

Since many people with this disorder are embarrassed or ashamed to be labeled "depressed," they may be reluctant to raise the subject with a clinician.

Sometimes the symptoms are the leading edge of another one of the mood disorders, such as

• major depression — a form of depression with symptoms that may be shorter in duration, but with severe symptoms
• bipolar disorder — depressive episodes occur, but also periods of elevated or irritable mood called manic episodes
• cyclothymic disorder — a milder form of bipolar disorder

There are no laboratory tests to diagnose persistent depressive disorder. (However, a doctor may order tests to investigate medical conditions that can be a cause of depressive symptoms, such as thyroid disease or anemia.)

Expected duration

Persistent depressive disorder can start early in life, even in childhood. There can be ups and downs in mood, but lower moods dominate and are persistent. Treatment can reduce how long it lasts and the intensity of the symptoms.

Prevention

There is no known way to prevent persistent depressive disorder.

Treatment

The best treatment is a combination of psychotherapy and medication.

The most helpful type of psychotherapy depends on a number of factors, including the nature of any stressful events, the availability of family and other social support, and personal preference. Therapy will usually include emotional support and education about depression. Cognitive behavioral therapy is designed to examine and help correct faulty, self-critical thought patterns. Psychodynamic, insight-oriented or interpersonal psychotherapy can help a person sort out conflicts in important relationships or explore the history behind the symptoms.

People with persistent depressive disorder who think that "feeling blue" is just part of their life may be surprised to learn that antidepressant medication can be very helpful. Antidepressants recommended for this disorder are the selective serotonin reuptake inhibitors (SSRIs such as fluoxetine), serotonin-norepinephrine reuptake inhibitors (SNRIs such as venlafaxine), mirtazapine and bupropion.

Side effects vary among these choices. Problems with sexual functioning are common in most except bupropion. Anxiety may increase in the early stages of treatment, although that feeling usually subsides. Although it is relatively uncommon, any psychoactive medication can make a person feel worse rather than better. Based on concerns that in rare cases these drugs can cause the onset of suicidal thinking, the U.S. Food and Drug Administration required antidepressant manufacturers to put prominent warning labels on their products.

The scientific community continues to debate how great the risk of suicide is when antidepressant treatment is started. Many experts take the position that — in the population as a whole — antidepressant treatment has reduced the number of suicides. They worry that the black box warnings have scared off people who might otherwise benefit from the drugs. Others note that doctors and patients should stay alert to the possibility that suicidal thinking can be triggered by an antidepressant. Both arguments have merit.

In fact, the risk of leaving depression untreated is probably far greater than the risk of treatment with an antidepressant. But a small number of people using the medications do feel strikingly worse rather than better when they take them. The best way to avoid danger is to monitor your response to any medication carefully. You should therefore keep all follow-up appointments and immediately report any troubling changes to your doctor.

Older antidepressants — tricyclic antidepressants and monoamine inhibitors — are still in use and can be very effective for those who do not respond to the newer medications. In all, there are dozens of antidepressants available. Any may be worth trying depending on the situation.

It usually takes two to six weeks of antidepressant use to see improvement. The dose usually must be adjusted to find the right dose for you. It can take up to a few months for the full positive effect to be seen.

Also, the first medication may not work for you. You may need to try several different antidepressants before finding one that provides relief.

Sometimes, two different antidepressant medications are prescribed together, or your doctor may add a drug from a different class to your treatment, for example, a mood stabilizer or antianxiety medication. Antipsychotic medication in low doses is occasionally very useful for symptoms that have otherwise been resistant to treatment. It can sometimes take persistence to find the combination that works best.

When to call a professional

Contact a health care professional if you suspect that you or a loved one has this disorder.

Prognosis

Treatment may improve the duration and intensity of symptoms. In many people, the symptoms go away completely. Without treatment, the illness is more likely to persist, the person is likely to have a reduced quality of life and has an increased risk of developing major depression.

Even when treatment is successful, maintenance treatment often is required to prevent symptoms from returning.

Additional info

National Institute of Mental Health
http://www.nimh.nih.gov/

National Alliance on Mental Illness
http://www.nami.org/

American Psychiatric Association
http://www.psychiatry.org/

American Psychological Association
http://www.apa.org/