Pleasant events, activity schedules, and depressions.

Three groups of 10 Ss, (depressed, psychiatric controls, and normal controls) were used. The 6s rated their moods and also indicated the number of "pleasant" activities engaged in each day over a period of 30 days. A significant association between mood and pleasant activities was found. There were large individual differences in regard to the magnitude of the correlation between mood and activity, but differences between groups failed to attain statistical significance. The results are interpreted as consistent with the major tenet of the behavioral theory of depression, that is, that there is an association between rate of positive reinforcement and intensity of depression.