Under the ICD‒10 Classification of Mental and Behavioral Disorders, reaction to severe stress and adjustment disorders（F43）is unique in that the disorders are defined by a stressor which caused the disorder, along with the specific psychiatric symptoms. Acute stress reactions（F43.0）, post‒traumatic stress disorder（PTSD）（F43.1）, adjustment disorder（F43.2）, and other reactions to severe stress are grouped into this category. Major conceptual change in F43 is discussed and will be proposed upon the next revision of the ICD. The proposal will include the removal of acute stress reactions from F43 to normalize such reactions, including PTSD and complex PTSD under traumatic stress disorder, introducing prolonged grief disorder, and a redefining of adjustment disorder.
 Further discussion and field testing of this proposed definition will follow before the release of ICD‒11. There are claims that the disorder concept, typical clinical features, and its way of formulation are based on Western views and, consequently, operational classification is difficult to use in Asian cultures and societies. There are multiple avenues to provide feedback during the process of the revision；thus, more input from Japanese psychiatrists is awaited.