Psychological co-morbidity has been associated with a range of disease conditions, including cancer. Depression and anxiety are the most frequently reported psychological disorders, and have been associated with impaired quality of life, reduced treatment adherence, and impaired immunoregulation and disease recovery. Despite the importance of detecting and treating psychological co-morbidity, physicians are often unable to identify patients in need, and the clinical utility and validity of current ultra-short screening measures have been questioned. It is proposed that in order for a brief screening measure to provide a highly specific, sensitive, and valid indication of patients'level of depression and anxiety;it must incorporate information concerning possible moderators of this psychological distress. The current application is therefore aligned with the goals of the Co-morbidity Research Program of the NIMH, and will seek to improve the detection of psychological co-morbidity through the development and clinical implementation of a new, brief screening measure, the Patient Health Survey. Data from four hundred cancer patients (current and post-treatment) will be used to validate and refine a preliminary version of the Patient Health Survey. Sensitivity and specificity values will be computed using data from fifty additional patients who will be recruited to complete a clinical interview and valid but lengthier measures of depression and anxiety. The final version of the Patient Health Survey will be piloted within a clinical setting using a tablet touch-screen computer, in partnership with Varian Medical Systems. Clinical staff will be trained in the use of the Patient Health Survey and preliminary feedback garnered from physicians and nurses on its clinical utility and pilot implementation. Specifically, the current application will seek to: (1) Validate and refine the recently developed Patient Health Survey using exploratory and confirmatory factor analysis and item-based analyses;(2) Develop a scoring algorithm that takes into account moderators of distress, and assess the sensitivity and specificity of the Patient Health Survey using Receiver Operating Curves;and (3) Assess the preliminary pilot implementation of the Patient Health Survey in a clinical setting through feedback from health professionals after one month of use. This application possesses great relevance to public health in that the Patient Health Survey, once fully implemented, will provide health-care providers with a highly sensitive and valid screening measure for depression and anxiety. It is hoped that the Patient Health Survey will reinforce the role of mental health services in a medical setting, and thus contribute to the provision of comprehensive health care in the USA.