The grouping of disorders specifically associated with stress in the 11th revision of the International Classification of Diseases World Health Organization [WHO], 2023) replaces the ICD-10 grouping of reaction to severe stress and adjustment disorders. Although the onset and course of many mental disorders can be influenced by past and current stressors, this grouping acknowledges that some disorders are so intimately connected with stressful events that they could not have occurred in their absence. At the same time, most people do not develop a disorder even when faced with a severe stressor, so psychological, social, and biological vulnerabilities also contribute to these disorders. Disorders specifically associated with stress include posttraumatic stress disorder (PTSD), complex PTSD, prolonged grief disorder, and adjustment disorder, which are the focus of this chapter. The ICD-11 grouping of disorders specifically associated with stress also includes reactive attachment disorder and disinhibited social engagement disorder, which are not discussed in this chapter. Both of these last two disorders are typically diagnosed in young children with a history of grossly inadequate child care (e.g., severe neglect, maltreatment, institutional deprivation) and are not commonly seen in general practice.The principles of clinical utility and global applicability that underpin the ICD-11 suggest that, where possible, diagnostic requirements should be simplified, describing disorders with the most parsimonious set of distinctive