Based on the extensive characterization of communication pathways between the nervous system and the immune system, there has been increasing interest in the impact of the nervous system on the development and expression of disorders involving the immune system and the contribution of the immune system to psychiatric disease. A vast literature has documented the impact of various stressors on a wide array of immune partners, and the specific neuroendocrine pathways involved have been elucidated. The impact of cytokines on neuroendocrine function and behavior has also been determined, and the relevance of cytokines to the pathophysiology of depression has become an exciting new research frontier. This article provides a foundation for integrating neuroendocrine-immune interactions into the formulation of neuropsychiatric and immunologic disease.