Phenomenological differences between acute and chronic forms of major depression in inpatients.

BACKGROUND: Chronic forms of depression are highly prevalent especially in inpatient settings. Defined only by episode duration greater than 2 years, heterogeneous diagnoses like dysthymic disorder, double depression, major depression and recurrent major depression are included. Chronic depression is considered difficult to treat, although its distinguishing characteristics remain unclear. AIMS: The purpose of the present study was empirically to approach proposed differences between acute and chronic forms of depression.
METHODS: 80 psychiatric inpatients positively screened for depression and diagnosed with the Composite International Diagnostic Interview (CIDI), completed a set of questionnaires regarding symptom severity (a simplified version of the Beck Depression Inventory), dysfunctional attitudes (Dysfunctional Attitudes Scale), ruminative response style (Response Styles Questionnaire, Why Ruminate Scale) and interpersonal problems (Inventory of Interpersonal Problems; IIP).
RESULTS: 30 patients were diagnosed with chronic forms of depression; 34 patients with acute depression. Patients did not differ regarding symptom severity, ruminative response styles, all but one subscales of the IIP or presence of comorbid post-traumatic stress disorder. However, chronic depression did show higher dysfunctional attitudes than acute depression, and reported higher rates of socially avoidant behavior.
CONCLUSIONS: In line with previous findings, acute and chronic forms of depression differed in dysfunctional attitudes, which might actually reflect a distinguishing pattern of chronicity. Chronic depression patients also reported higher socially avoidant behavior, which might be crucial to focus in treatment. Surprisingly, other variables that are assumed to characterize chronic depression could not be confirmed as distinguishing features. Future research should take etiological aspects into account.