Generalized anxiety disorder (GAD) is characterized by excessive worry about a variety of topics. In addition to the presence of uncontrollable and persistent worry, the diagnosis of GAD requires the presence of at least three out of six symptoms reflecting physiological or psychological arousal that accompany the worry. These include feeling keyed up, restless, or on edge; difficulty concentrating or having one's mind go blank due to worry; disrupted sleep due to worry; muscle tension; irritability; and fatigue. To understand the psychopathology of generalized anxiety disorder, one needs to view it from a biopsychosocial perspective. This chapter reviews research findings on the neurobiology and psychophysiology of GAD and the social and psychological correlates of this disorder. Individuals with GAD may have difficulties with emotion regulation. More specifically, individuals with GAD may experience more intense emotions; have more difficulty naming, understanding, and accepting emotions; and demonstrate difficulty regulating negative emotions that do occur.