**1. Introduction**

Stroke is one of the leading causes of long-term disability in the United States and is the third leading cause of mortality [1]. Brain parenchyma is densely packed with millions of neurons, where any assault such as an ischemic or hemorrhagic stroke can leave a patient with debilitating deficits [2]. A few of these deficits include the inability to speak or understand language; loss of vision, complete paralysis of one side of the body, quadriplegia, persistent balance issues, and loss of the ability swallow independently. Neuropsychological changes are also very common and well documented in poststroke patients; however, the number of patients that suffer from these changes are grossly underestimated [3].

More than one-third of all stroke survivors experience some form of depression [4]. Depression after a stroke can manifest in many different ways including feelings of anger, frustration, hopelessness, guilt, mental slowing, fatigue, irritability, changes in appetite, social withdrawal, loss of interest in activities they once found enjoyable (also known as anhedonia), or even suicidal thoughts [2]. Patients that suffer from poststroke depression, often have these symptoms missed or undertreated. Recovery and rehabilitation can be adversely affected if post stroke depression is not adequately treated. This can result in increased length of stay at postacute care facilities, increased morbidity, decreased quality of life and even increased mortality [5]. Numerous depression scales have been used to define poststroke depression including the Beck Depression Inventory (BDI), Montgomery-Åsberg Depression Rating Scale (MADRS), Centre for Epidemiologic Studies Depression

scale (CES-D), Zung self-rating depression scale and the Hamilton Depression Rating Scale (HDRS) [5]. Post stroke depression has a great impact on the healthcare system as well as on the individual patient. In this chapter, we will examine all aspect of depression as it relates to stroke by using these scales and large metaanalyses to define post-stroke depression, and assess how it relates to stroke and recovery.
