Many measures of depression severity appear confounded by including depressive sub-typing features. We report the design of a brief (11 item) self-report scale of depression severity (the AUSSI), assessing both mood state and social impairment domains, and designed to be independent of sub-typing features. Mood severity and functional impairment scores demonstrated some independence in a sample of 360 patients. Patients with a 'melancholic' depressive type (categorised by four differing systems) differed from residual 'non-melancholic' depressed patients by having higher impairment scores, but the assigned groups did not differ, in the main, by mood severity scores. Advantages of the measure are summarised.