Since the DSM-III, the category of dysthymia includes patients that were previously considered as neurotic, reactive, characterological, temperamental, minor or atypical depressives as opposed to a category of endogenous, autonomous, morbid, major or typical depressives. Despite certain confusion, the need for a nosological category is very important for patients suffering from years of depressive mood, with a significant impact on their life-styles and adaptation, as they can benefit enormously from modern antidepressant treatments. DSM-IV and ICD-10 describe dysthymia in a very similar way although there are significant differences. The differences are the consequence of the lack of sufficient scientific data in some points and the need to take a decision, but also to indicate areas for future research. Other differences are the consequence of major discrepancies in basic perspectives of the classifications (ie, the importance given to disablement for the diagnosis). The similarities between both classifications allow the use of either of them for most purposes. Research on the different classifications should help in better defining the concept of dysthymia and mood disorders in general (ie, the cut-off points between them) and of psychiatric nosology.

Platelet monoamine oxidase (MAO) activities were assessed in 82 patients, 57 females and 25 males, who were admitted to the medical ward of a general hospital after a suicide attempt. The enzyme activities were compared to the activities of healthy subjects, 35 females and 26 males. In addition, MAO activities were analyzed in relation to sex, psychiatric diagnosis, mode of attempt, drugs ingested, and previous attempts. Compared to normal controls, only female patients showed lower MAO activities. In the male population, lower activities were found in the subgroup of patients who had made previous attempts. In relation to diagnosis, analysis performed in the female population revealed lower MAO activities in the dysthymic and personality disorder, and not in the adjustment or major affective disorder subgroups. MAO activities were not related to the violent mode of attempt, the type of medication used, or the score in the Beck Suicidal Intent scale. The finding of low platelet MAO activities in dysthymic disorder, indicates the need for further studies of biological variables in this underdiagnosed and undertreated diagnostic group.

Open trials with tricyclics, classical monoamine oxidase inhibitors (MAOIs) or lithium in dysthymia yielded a response rate in 45% of subjects. A long-term treatment of dysthymia with 276 patients treated during 4 years with either moclobemide, tranylcypromine or a combination of amitryptiline plus chlordiazepoxide is described. After discontinuation there was a relapse rate of 89.1%. The controlled studies with tricyclics, MAOIs, reversible inhibitors of monoamine oxidase (RIMAs), specific serotonin reuptake inhibitor (SSRIs) or benzamides showed that drugs well-tolerated work better in dysthymia, due to the fact that the treatment must be long-term. Sertraline was studied vs placebo or imipramine in primary dysthymia. Moclobemide, imipramine and placebo were also studied in 315 patients. Mean doses were 650 mg/d of moclobemide and 203.2 mg/d of imipramine. Moclobemide and sertraline were both efficacious and well tolerated. In a long term treatment the clinician should assess the risk-benefit ratio. Dysthymic patients are very sensitive to unwanted effects and compliance is a serious issue.

A two-part survey of French General practitioners was carried out to determine attitudes and diagnostic criteria for definition of atypical depression, major depressive episodes, and anxiety disorder. Following a preliminary phase in which 90 physicians were interviewed, 500 general practitioners received detailed questionnaires based upon DSM III-R criteria, as well as supplementary questions based upon the Leibowitz and Akiskal criteria. Principal criteria analysis and regression analysis were carried out on the 280 analyzable files received. Results showed that anxiety disorders were primarily defined in terms of somatic criteria, and that there were a number of factors common to anxiety and depression. Minor depression was also defined primarily on the basis of somatic complaints, together with loss of energy and fatigue. Major depression was defined primarily by asthenia, apragmatism and loss of drive, together with less strongly weighted cognitive factors (sadness, Pessimism, inhibition, etc). From a dimensional standpoint, depression is defined as a “vital deficit”, with a failure to cope with social and environmental demands. It is interesting to note that the duration criterion was not considered to be of nosological relevance by the physicians, and was generally ignored in the definition of mental pathologies. The international subtyping of depressive disorders does not form part of the Practice of French practitioners, who prefer to retain the older, psychosocial models.

The diagnosis of dysthymic disorder was created in DSM-III and maintained in DSM-IV to describe a depressive syndrome of mild to moderate severity of at least two years’ duration that did not meet criteria for major depressive disorder. The prevalence of dysthymic disorder is approximately 2% in the elderly population where subsyndromal depressions of lesser severity are more common. Dysthymic disorder was replaced in DSM-V by the diagnosis of “persistent depressive disorder” that includes chronic major depression and dysthymic disorder. In older adults, epidemiological and clinical evidence supports the use of the term “dysthymic disorder.” In contrast to young adults with dysthymic disorder, older adults with dysthymic disorder commonly present with late age of onset, without major depression and other psychiatric disorders, and with a low rate of family history of mood disorders. They often have stressors such as loss of social support and bereavement, and some have cerebrovascular or neurodegenerative pathology. A minority has chronic depression dating from youth with psychiatric comorbidity similar to young adults with dysthymic disorder. In older adults, both dysthymic disorder and subsyndromal depression increase disability and lead to poor medical outcomes. Elderly patients with dysthymic disorder are seen mainly in primary care where identification and treatment are often inadequate. Treatment with antidepressant medication shows marginal superiority over placebo in controlled trials, and problem-solving therapy shows similar efficacy. Combined treatment and collaborative care models show slightly better results, but cost effectiveness is a concern. Further work is needed to clarify optimal approaches to the treatment of dysthymic disorder in elderly patients.