The IOM Report states that by 2030, 20% of the population will be over 65. Currently, 60% of cancer diagnoses and 70% of deaths from cancer occur in this age group. Almost two-thirds of cancer survivors in this country are elderly and these percentages will continue to rise for the next 20 to 30 years. Depression is considered one of the top five concerns for the elderly and the prevalence of depressive disorders in older cancer patients ranges from 17-25%. Depression, throughout the spectrum from isolated depressive symptoms to major depressive disorder, is associated with decreased quality of life, deterioration in physical activities, relationship difficulties, caretaker burden, and greater pain. The economic burden of depression in the US has been estimated to be greater than 52 billion dollars a year. Yet, despite the high prevalence rates and deleterious effects of depression, elderly cancer patients are far less likely to be diagnosed with depression (major or minor) than any other age group. One reason for the underdiagnosis of depression in older cancer patients is that these patients may not report classic DSM-IV criteria. Self-report measures of depression are often an efficient and cost-effective way to identify depressive symptoms and make appropriate mental health referrals. However, there is a dearth of psychometric data establishing the validity of existing depression measurement tools in older cancer patients, and because these instruments are typically based on DSM criteria or classic symptoms of depression, it is unlikely that they can effectively assess depressive symptoms in this population. This proposal represents the first step in a program of research geared towards identifying, quantifying, and ultimately alleviating depression in older cancer patients, and will explore how older adults with cancer experience and express depressive symptomatology and develop a self-report scale tailored to this large, but under-recognized, population. The aims of this proposal are: 1) To identify the phenomenology of depression in older cancer patients, 2) To develop a set of indicators to identify depression in older cancer patients and operationalize these indicators in the form of questionnaire items, and 3) To evaluate the preliminary psychometric properties of a self-report measure of depression tailored to the needs of older cancer patients.