This study involves the description of the presence or absence of several theoretically relevant skill deficits in 35 cases of depression. Until recently, most research and theory about depression has been based on the assumption that this is a homogeneous disorder with one determinant common to all incidences. Theories proposed by Beck (1967), Lewinsohn (1974), Seligman (Abramson, Seligman & Teasdale, 1978), and Rehm (1977) are examples of unitary theories. It is argued that a comprehensive account of depression must involve a multivariate theory such as that proposed by Staats and Heiby (1985). The case study involves a preliminary uncontrolled test of the hypothesis that there exist several skills deficits that may determine depression. The findings suggest support for the possibility that the following skill deficits deserve further investigation for their role in depression aetiology and treatment: logical errors including misattributions, poor self-control skills, poor social skills in terms of excessive aggression and deficit assertiveness, and inadequate hedonic capacity in terms of deficit positive interests and excessive negative interests (anhedonia). Suggestions for future research are offered.