The term cyclothymia was established in 1880 by the German psychiatrist Karl Ludwig Kahlbaum. Kahlbaum wanted to emphasize the idea, that manic and depressive episodes are stages of the same disease.
The ICD-10 and DSM-IV describe the cyclothymia (also called cyclothymic disorder) as a disorder that is characterized by a persistent instability of mood, involving numerous episodes of depression and episodes of elation (hypomania), in which the depressive or hypomanic episodes, however, are not that pronounced that they meet the criteria of bipolar affective disorders or major depressive disorders.
Cyclothymia: Definition according to DSM-IV
According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) the cyclothymic disorder (DSM-IV 301.13) is diagnosed if a patient has experienced numerous episodes with hypomanic symptoms and numerous additional episodes of depressive symptoms for a period of at least 2 years, and if during this period no symptom-free interval of two months or more has occurred.
The episodes with hypomanic symptoms need to be characterized by a persistently elevated, expansive and/or irritable mood for at least 4 days duration.
Additionally, in the hypomanic episodes at least 3 (at least 4 if there is only irritable mood) of the following symptoms need to occur. Symptoms that are caused by antidepressant medication or physiological factors should not be taken into account:
- Overconfidence, elevated self-esteem or feelings of grandiosity,
- Decreased need for sleep,
- Increased talkativeness or pressured speech,
- Flight of ideas,
- Increased distractibility,
- Increased activity (social, occupational, educational, or sexually) or psychomotor agitation,
- Excessive involvement in pleasurable activities that attract a high probability of unpleasant consequences (such as unrestrained shopping, sexual escapades, etc.).
The hypomanic periods shall not be severe enough to cause significant social or occupational impairment or to require hospital admission. There must be no psychotic symptoms, since the disorder would otherwise meet the criteria for a manic or mixed episode.
During the first two years of the disorder (in children / adolescents one year) at no time an episode of major depressive disorder, a manic episode or a mixed episode must have occurred. In the later course of cyclothymic disorder so-called “superimposed episodes” may occur.
The symptoms must not be better accounted for by schizoaffective disorder. There must be no psychotic or delusional disorder. The symptoms must not be caused by the action of a substance (e.g. drugs or medication) or a physical illness factor.
The symptoms must cause clinically significant distress or impairment in social, occupational or other important areas of functioning.
The differential diagnosis includes the dysthymic disorder (DMS-IV 300.4), adjustment disorder with depressed mood (DMS-IV 309.0), bipolar disorder (DMS-IV 296.xx), major depressive disorder (DMS-IV 296.xx) or depressive disorder NOS (DMS-IV, 311).
The lifetime prevalence of cyclothymia is about 0.5-1%. The cyclothymia is more common among relatives of patients with bipolar affective disorder. Some patients with cyclothymia eventually develop a bipolar affective disorder.
The treatment of cyclothymia has been poorly studied. As far as is known, if necessary pharmacotherapy with lithium, carbamazepine or valproic acid may be helpful. The use of antidepressants may be critical, as the sole administration of antidepressants may result in approximately half of patients with cyclothymia in the occurrence of hypomanic or manic symptoms.