Here is an excerpt from a manuscript I have written that includes a summary of the epidemiology of cyclothymia. - - - Akiskal (1983) notes that while cyclothymia differs from bipolar disorder in several ways such as: (1) a less developed symptom profile with less severity; (2) the extremely rare occurrence of psychotic features; (3) brief cycles; and (4) an irregular cycling pattern with few normal mood periods, cyclothymics do have some striking similarities to bipolar patients. These include: (1) a shared phenomenology of illness; (2) familial prevalence similar to bipolars; (3) continued cycling in the absence of chemotherapy; and (4) induced hypomania upon administration of antidepressant drugs. Although cyclothymia has been conceptualized as a characterological disorder, Akiskal et. al. (1979) consider this description to stem from the incorrect assumption that social factors including substance abuse, interpersonal conflict and episodic promiscuity are primary rather than secondary to the affective dysfunction. Further, during the course of the illness, cyclothymics like bipolars often experience intermittent difficulties with hypersomnia and hyposomnia, fluctuation in self-esteem ranging from disparagement to grandiosity, alternating intervals of mental confusion and indifference followed by mental sharpness, uneven performance on the job and recurrent periods of ntroversion or uninhibited social activity. In addition to these similarities, Akiskal (1983) and Akiskal et al. (1979) feel the most compelling evidence for classifying cyclothymia as an affective disorder and linking it to bipolar illness has been the family studies, response to chemotherapy and the relapse rate following treatment. Comparing the rate of bipolar illness among first degree relatives of patients diagnosed with either cyclothymia or Bipolar I, 30% of the cyclothymic relatives and 26% of the Bipolar I relatives also earned diagnoses of bipolar illness. Considering now the response rate to antidepressant chemotherapy, 60% of the cyclothymics while only 20% of the non-affective personality disorder patients improved with administration of lithium. Additionally, hypomania was often induced by the drug intervention. Following the end of chemotherapy treatment, 36% of the cyclothymics began to experience more severe cycling while only 5% of the non-affective personality disorder group went on to develop the biphasic course of the illness. - - - Basically, if you wish to go to the source, the work of Akiskal and the work of Depue has been the most helpful to me in getting up to speed with the study of cyclothymia. Good Luck! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- =-=-=-=-=-= = David M. Fresco = = Department of Psychology = = CB#3270, Davie Hall __o = = Chapel Hill, NC 27599 \<, = = Internet: `,/'(*) = = (*) . ./""" = = Voice: (919) 962-5082 """" = = Fax: (919) 962-2537 = =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- =-=-=-=-=-=