2. Develop the module for implementing computer-based Problem-Solving Treatment (PST). Currently, problem-solving treatment is done using a practitioner who guides the patient through this structured therapy and follows their progress. These practitioners are trained to administer the therapy through a formalized training program that incorporates a workbook and instructional videos. These materials are well suited for presentation via multimedia on computers to make the treatment self-guided. The PST intervention will be modified from its current video/workbook form to a computer-based form that can be used by astronauts or other professionals who are suffering from depression.