Dysthymic disorder: clinical characteristics in relation to age at onset

The variability in the clinical presentation of dysthymia has given rise to a rich debate in literature, and various hypotheses have been proposed. One is that the clinical presentation differs in relation to age at onset. The aim of the study was to evaluate differences in socio-demographic and clinical characteristics in a sample of patients with dysthymia (DSM-IV), in relation to age at onset.

84 consecutive outpatients with a diagnosis of dysthymia (DSM-IV) were studied. All subjects were evaluated by a semistructured clinical interview and the following rating scales: HAM-A, HAM-D, MADRS, Paykel's Interview for Recent Life Events.

23.8% of the sample had early-onset (<21 yrs) dysthymia. Patients with early-onset disorder were significantly younger at the observation, more frequently female and single. They had a significantly longer duration of illness and in a significantly higher percentage had already received a specialist treatment before admission in the present trial. No differences in the frequency of symptoms were observed. A significantly higher percentage of patients with late-onset disease reported at least one stressful event in the year preceding the onset of dysthymia. A positive history of major depression was significantly more common among the early-onset group; social phobia, panic disorder and conversive disorder were also more frequent in this group. The late-onset patients frequently presented generalized anxiety disorder, substance abuse and somatization disorder.

The study is retrospective and enrolls a limited number of cases.

The present study agrees with other reports on the differences in clinical presentation of dysthymia according to age at onset. Although they are not actually related to age at onset, some interesting findings emerged in the symptomatological characterization of the disorder, referring to the diagnostic criteria proposed in DSM-IV.