Despite abundance of treatment outcome studies, researchers have failed to identify a treatment for depression that works for all individuals. A possible solution is to individualize depression treatment. To test whether this strategy will be more effective, an assessment tied to theory of intervention is necessary. This article describes a current effort to develop a new measure of depression, the functional assessment of depression (FAD), based on behavioral assessment strategies. A factor analysis and cluster analysis were performed in an attempt to identify information provided that might prove useful in treatment planning. Future efforts to explore the incremental validity and treatment utility of the FAD are described. (Contains 9 notes, 3 tables, and 7 figures.)