DYSTHYMIA AND OTHER MOOD DISORDERS

THE HARVARD MENTAL HEALTH LETTER, MAY 1991

The word "depression" can be used to describe anything from a passing mood to a chronic illness with severe physical as well as psychological symptoms. Depression is regarded as a psychiatric disorder when it is deep and persistent enough to interfere with work, friendships, family life, and physical health. 

Common symptoms of major, or severe, depression are inconsolable misery, despair, guilt, suicidal thoughts, low self-esteem, irritability, a sense of helplessness, inability to concentrate or make decisions, loss of interest in life and incapacity for pleasure.  Some depressed patients have expressionless faces, move slowly,
and speak tonelessly. Others pace, weep, and wring their hands in agitation. Disordered mood also takes the form of physical symptoms -- chronic fatigue, loss of appetite, insomnia (or sometimes oversleeping and overeating), upset stomachs, constipation, backaches, headaches, and other pains. Episodes of major depression usually last several months and may recur throughout a lifetime. A disorder with similar but longer-lasting
and milder symptoms is Dysthymia (the Greek roots of the word mean "bad state of mind" or ("ill humor"). 

By the standard psychiatric definition, this disorder lasts for at least two years, but is less disabling than major depression; for example, victims are usually able to go on working and do not need to be hospitalized. About 3 percent of the population will suffer from Dysthymia at some time -- a rate slightly lower than the rate of major depression. Like major depression, Dysthymia occurs twice as often in women as it does in men. It is also more common among the poor and the unmarried. The symptoms usually appear in adolescence or young adulthood but in some cases do not emerge until middle age. At first the disorder may take the form of poor school performance, social withdrawal, shyness, irritable hostility, and conflicts with parents. Sometimes the symptoms include physiological abnormalities that also occur in major depression, such as short REM latency (dreaming that starts unusually early in the night) and other sleep irregularities. 

Dysthymia is common in the children of parents with major depression,  and the rate of mood disorders in the families of people with the early-onset variety is as high as 50 percent. The high rate of family transmission suggests, although it does not prove, that the disorder has a genetic basis.

It is also a serious illness that often becomes worse. Most persons with Dysthymia eventually develop major depression; nearly half of patients treated for depression are suffering from this "double depression." They differ very little from other patients with major depression in biological, social, and psychological functioning, or in the rate of mood disorders in their families. After recovery from major depression, a milder chronic condition often persists for years, heightening the danger of relapse. This residual depression is not diagnosed as Dysthymia unless the patient had Dysthymia before developing major depression.

DIAGNOSTIC AMBIGUITY

Similar symptoms may arise not only from primary Dysthymia and residual depression but also in connection with anxiety and panic disorders, drug and alcohol dependence, eating disorders, attention deficit disorder, and chronic physical illnesses. At least three-quarters of patients with Dysthymia have some other psychiatric or medical disorder as well. If it can be determined that the other illness came first, Dysthymia is regarded as secondary, but often the effort to sort out the symptoms and disentangle cause and effect is futile.

Diagnostic confusion and ambiguity are even greater when personality is taken into account. Many symptoms of this long-lasting disorder can be interpreted as personality traits, especially when they appear early in life. Timidity, brooding, low self-esteem, submissiveness, and social maladroitness are typical characteristics of dependent, obsessive-compulsive and avoidant personality disorders as well as Dysthymia. Until 1980, when it was removed from the official manual of the American Psychiatric Association, the diagnosis of depressive personality was given to many cases of what is now called Dysthymia. That term, or the related "characterological depression," is still favored by many European and some American psychiatrists. They argue, for example,
that depressive personality can be distinguished from Dysthymia because it is more common in men and less often associated with depression in family members. But now the majority opinion is simply that many people have both Dysthymia and a quiet, passive, gloomy personality.

Other persons vulnerable to chronic depression are moody, demanding, self-dramatizing, complaining, and impulsive. Their symptoms may include alcoholism and other drug abuse, intense anger and anxiety, hypersensitivity to both criticism and praise, and constantly changing psychosomatic complaints. Alcoholism and criminal activity, rather than mood disorders, are common in their families. Their personalities are often described as histrionic, borderline, or antisocial. Some patients in whom these symptoms are combined with others (oversleeping, overeating, a leaden feeling that overcomes the body in waves) may be suffering not from Dysthymia but from a distinct disorder known as atypical depression or hysteroid dysphoria. Still another name for related conditions is "depressive spectrum disorder" -- a term that deliberately blurs the distinction between personality and mood disorders.

Cyclothymia is a mood disorder related to both personality disorders and Dysthymia. In this illness the alternating mania (uncontrolled elation) and depression of bipolar disorder take a milder and less disabling form. Cyclothymic persons endure short and irregular cycles of energetic activity and lethargy, optimism and pessimism, insomnia and oversleeping, jocularity and tearfulness, arrogance and self-pity, passionate involvement and sudden loss of interest. Their marriages fail; they periodically abuse alcohol and other drugs and repeatedly change jobs and homes. Just as people with dysthymia usually have episodes of major depression, people with cyclothymia are vulnerable to both major depression and mania. But ordinarily their erratic behavior and troubled family lives are more obvious than any underlying mood cycle. Many of their symptoms resemble borderline or histrionic personality, and at one time they were given the diagnosis of cyclothymic personality disorder.  This diagnostic indecisiveness results from the complicated relationship between personality and mood. It is an
oversimplification to say that personality is enduring and mood is episodic, or even to say that personality is more fundamental and pervasive than mood. A personality trait, by definition, is a susceptibility to certain states of mind and an inclination to certain kinds of behavior, so the symptoms of personality and mood disorders overlap. There is no sharp distinction between emotional weather and emotional climate in individuals. 

Certain personality types are more vulnerable to mood disorders.  People are more likely to become depressed and slower to recover if they are either withdrawn, submissive, and unreasonably self-critical, or unstable, impulsive, and hypersensitive to loss. On the other hand, defective mood regulation may cause disturbances in a person's social and emotional life that resemble character pathology. Another possibility is that personality and mood disorders often coincide simply because both are so common.

TREATMENT

The choice of treatment may be influenced by these difficult distinctions between personality and mood disorders and among the various types of mood disorder. Psychiatrists now find Dysthymia and other mood disorders in many cases where they would once have diagnosed a personality disorder, mainly because they have
discovered that mood-regulating drugs are an effective treatment for a wider range of symptoms than they once suspected. Tricyclic antidepressants, the standard treatment for major depression, are also useful for both Dysthymia and residual depression.

In one study 13 percent of patients recovered from Dysthymia with a placebo and 59 percent with Imipramine (Tofranil ®) at the same dose used to treat major depression. The newer non-tricyclic antidepressant Fluoxetine (Prozac ®) may work even better, with fewer side effects. According to some authorities, the best treatment for symptoms identified as atypical depression or Hysteroid Dysphoria is another type of antidepressant drug, an MAO (monoamine oxidase) inhibitor. Lithium, the standard treatment for bipolar illness, can also be used for Cyclothymia. Most psychiatrists would prescribe one of these drugs to patients with a diagnosis of primary or secondary Dysthymia, Cyclothymia, atypical depression, depressive spectrum disorder, or even some
personality disorders.

But drugs are often ineffective when the depressed patient is angry, self-dramatizing, hypersensitive, "mood-reactive" rather than exhausted and inconsolably gloomy; and even when drugs provide some relief, social and psychological problems must usually be addressed in psychotherapy. Patients without serious personality disturbances can make use of supportive psychotherapy, which offers advice, reassurance, and sympathy.  Counseling on the management of stress is also important. Cognitive therapy is used to alter patients' self-defeating thoughts; behavioral treatment may help them unlearn learned helplessness. Psychodynamic therapists identify and resolve unconscious conflicts derived largely from childhood experience. Interpersonal psychotherapists concentrate on restoring self-esteem and improving communication with friends, families, and co-workers. Social skills training may be important for people with early-onset Dysthymia who have never learned how to cope with the adult world. Successful treatment of alcoholism, panic disorder, or eating disorders usually relieves the associated Dysthymia.

But in many cases the symptoms are hard to recognize and classify, and the response to treatment is unpredictable. Most people with Dysthymia and related disorders see only their family doctors, who may misdiagnose them, especially if the main complaints are physical. Many patients do not think of themselves as depressed and are relieved when told they have a treatable illness. Unfortunately, mental health professionals are usually consulted only when major depression develops, although Dysthymia alone may lead to alcoholism or suicide. Even when it is recognized, Dysthymia, like personality disorders, is difficult to treat. The longer a depression lasts, the slower the recovery. One study found that two years after treatment, according to their own reports, 75 percent of patients with major depression but only 43 percent of patients with Dysthymia had recovered. Another study found that on the average Dysthymia lasted five-and-a-half years.

FOR FURTHER READING

Hagop S. Akiskal and Radwan F. Haykal. Dysthymic, "atypical," and
residual depressive disorders. In Anastasios Georgotas and Robert
Cancro, eds. Depression and Mania. New York: Elsevier, 1988.

James H. Kocsis and Allen J. Frances. A critical discussion of
DSM-III dysthymic disorder. American Journal of Psychiatry,
144:1534-1542 (December 1987). Katharine A. Phillips, John G.
Gunderson, Robert M. A. Hirschfeld, and Lauren E. Smith. A review
of the depressive personality. American Journal of Psychiatry,
147:830-837 (July 1990).

Myrna M. Weissman, Philip J. Leaf, Martha Livingston Bruce, and
Louis Florio. The epidemiology of dysthymia in five communities:
rates, risks, comorbidity, and treatment. American Journal of
Psychiatry, 145:815 819 (July 1988). R. Alnaes and S. Torgensen.
Personality and personality disorders among patients with major
depression in combination with dysthymic or cyclothymic disorders.
Acta Psychiatrica Scandinavica, 79:363-369 (1989).

President and Fellows of Harvard College, 1991
Reprinted with permission.