We are witnessing an explosion of interest in endocrinology in psychiatric illness. This interest is two-fold. Psychiatric illness is profoundly influenced by the endocrine milieu. This includes normal and cyclical changes in hormone levels as well as abnormal hormone levels such as occurring under conditions of profound stress. Secondly, classic endocrine disorders are a cause of psychiatric illness. Perhaps more interestingly, subtle endocrine alterations can lead to subtle to profound psychiatric symptoms. How may we influence neuroendocrine states to alter the outcome of psychiatric illness.? My initial study of endocrinology and the emerging field of hormone receptors kindled my interest in psychiatry in the 1970s. While on the faculty at the University of Iowa , I discovered that many patients were poorly served by psychiatry because they presented with subtle endocrine abnormalities and psychiatric illness that was poorly understood and therefore poorly treated by specialists in endocrinology and psychiatry. This led me to pursue a career in psychiatry and endocrinology and ultimately psychoneuroendocrinology. This field now includes an international society, The International Society of Psychoneuroendocrinology and a monthly journal, Psychoneuroendocrinology. What can be learned from seeing a psychoneuroendocrinologist? Why should you see this specialist? What is Psychoneuroendocrinology? Psychoneuroendocrinology is the clinical study of hormone fluctuations and their relationship to psychiatric illness. It is subtle blend of endocrinology and psychiatry. The brain is increasingly viewed as an organ secreting hormones. This observation cements the relationship between hormones and behavior.