Diurnal variations of mood in psychiatric patients of different nosological groups.

In order to investigate whether diurnal variations of mood (DV) are pathognomonic for the diagnosis of endogenous depression, 130 patients and 21 healthy control subjects were examined. The patients differed in the type of primary disease (neurotic, endogenous depression, depression in schizophrenia). All subjects recorded their subjective mood on the Visual Analogue Scale every morning and evening over a period of 3 weeks. In addition, they were classified by expert rating according to clinical criteria as belonging to one of the three different groups of rhythmic type: morning type, evening type, indifference type. The results reveal that DV occur frequently but that they are nonspecific. No correlation between nosological diagnosis and rhythmic type was found. It follows that DV, therefore, cannot improve sample homogeneity in studies on psychoactive drugs.