Self-system therapy (SST) for depression is a structured, short-term, evidence-based treatment approach that targets motivational deficits in depression. The treatment is grounded in an extensive research literature on self-regulation, and it translates that empirical work into therapeutic strategies aimed at enhancing effective goal pursuit in clients with depression. Studies have demonstrated that SST is superior to cognitive therapy for depressed clients with specific self-regulatory deficits and have shown that SST works in part by restoring adaptive self-regulation. Presented in a simplified format, the Therapist Guide provides clinicians with the critical theoretical background that forms the foundation of SST and includes worksheets to aid in treatment planning. The core SST interventions are presented within a 16-week course of therapy. Detailed descriptions of these interventions are provided along with an optional module for managing perfectionism, which is prevalent among clients with depression. The accompanying Client Workbook explains the core SST concepts using concrete examples and includes worksheets that can be used to enhance learning and at-home application of the skills.