Poststroke Depression

Poststroke depression (PSD) is a relatively frequent psychiatric comorbidity with prevalence rates ranging between 30% and 50%. Typically, PSD tends to occur between the third and sixth month following a stroke and may be identical to primary major or minor depressive episodes. However, some elderly patients (aged 65 years and older) with bilateral silent or overt subcortical strokes may present a different type of depression in which depressed mood is associated with cognitive disturbances with impairment of executive functions, psychomotor retardation, poor insight, and impaired activities of daily living. This type of PSD is known as vascular depression. Stroke and depressive disorders have a bidirectional relation, whereby not only are patients with stroke at greater risk of developing a PSD, but patients with a history of depression are at greater risk of developing a stroke. This relation is mediated by the existence of common pathogenic mechanisms operant in both conditions, which include anti-inflammatory processes, a hyperactive hypothalamic-pituitary-adrenal axis that can result in a hypercoagulable state, as well as cardiac disturbances. The presence of PSD is associated with a worse recovery of activities of daily living, cognitive disturbances, and a higher mortality risk. Thus, early identification of PSD is of the essence so that treatment can be started without delay.