Sleep difficulties are a major issue in psychiatric illness and care and a significant management issue in treatment. Sleep disorders have been increasingly associated with worsening morbidity and mortality. It is important for providers to understand and manage the sleep difficulties produced/ exacerbated by psychiatric medications. Complex interactions between neurotransmitters can be triggered by psychotropic agents and can have widely varying effects on sleep architecture. This text incorporates the latest scientific advances in our understanding of the neurobiology of sleep-wake disorders and the effect of psychotropics on sleep architecture.