The depression treatment program developed through this project has the potential to help individuals receive an evidence-based treatment for depression who would otherwise not have access to it. Worldwide, depression is now the leading cause of disability, and in wealthier nations such as the United States, mental health disorders account for 4 of the 10 leading causes of lost productivity. A recent study of over 60,000 employees of large American companies found that 4.5% have high levels of psychological distress but that only 22% of them are receiving treatment. The annual cost to the United States in unearned income due to mental health disorders is $193 billion. Nonetheless, successful treatment of mental disorders generally returns individuals to functioning comparable to those who have no history of mental health problems. Effective, evidence-based treatments for depression do exist; however, there are major barriers to their widespread dissemination in the United States, including cost, transportation, availability, logistics, stigma, and training. The cost of behavioral health and psychiatric care is often borne directly by consumers and prohibitive for those with limited income. Moreover, the availability of services is limited, and many Americans lack adequate access to behavioral health professionals. Logistics of travel and scheduling pose barriers to receiving behavioral health care on Earth as well as in space. Taking the time off from work, arranging childcare, and potentially traveling a great distance to appointments all conspire against individuals receiving a sufficient dose of behavioral intervention. Additionally, the stigma of asking for mental health care -- in self-perception and in social and employment consequences -- can prevent individuals from asking for help when it is needed on Earth, just as in space. Finally, many Master's and Doctoral-level behavioral health professionals lack training in evidence-based treatment for depression. Practicing clinicians typically fail to adopt such treatments. Moreover, even when they are aware of the evidence-based guidelines and do attempt to provide them, the treatments are often not delivered effectively. If ultimately found to be effective, the problem-solving treatment program developed through this project could help overcome the barriers of cost, availability, logistics, stigma, and training, while potentially facilitating major improvements in public mental health. It could be rolled out in a mass scale, making an evidence-based treatment for depression available at any location, at any time. This computer-based depression treatment, with simple modifications and revisions, could be adapted for use in other isolated operational environments, such as polar research stations, submarines, commercial ships, oil rigs, and underwater research bases. Furthermore, even greater value could be derived by making similar psychosocial support systems available to the public in settings such as primary care practices, public and mental health centers, schools, social services offices, places of worship, military bases, prisons, and eventually at home or in any location, through broadband Internet.