ICD-10's F43.8. If, after treatment, a person with burnout continues to have persistent physical symptoms triggered by the condition, in Iceland they may be considered to have "somatic symptom disorder" (DSM-5) and "bodily distress disorder" (ICD-11). Further detail about the varied ways clinicians and others use ICD and DSM classification with burnout was published by Arno Van Dam in 2021. The US government's National Institutes of Health includes the condition as "psychological burnout" in its index of the National Library of Medicine, and provides a number of synonyms. It defines the condition as "An excessive reaction to stress caused by one's environment that may be characterized by feelings of emotional and physical exhaustion, coupled with a sense of frustration and failure." SNOMED CT includes the term "burnout" as a synonym for its defined condition of "Physical AND emotional exhaustion state," which is a subtype of anxiety disorder. The Diseases Database defines the condition as "professional burnout." Instruments In 1981, Maslach and Jackson developed the first widely used instrument for assessing burnout, the Maslach Burnout Inventory (MBI). It remains by far the most commonly used instrument to assess the condition. Consistent with Maslach's conceptualization, the MBI operationalizes burnout as a three-dimensional syndrome consisting of emotional exhaustion, depersonalization (an unfeeling and impersonal response toward recipients of one's service, care, treatment, or instruction), and reduced personal accomplishment. The MBI originally focused on human service professionals (e.g., teachers, social workers). Since that time, the MBI has been used for a wider variety of workers (e.g., healthcare workers). The instrument or its variants are now employed with job incumbents working in many other occupations. There are other conceptualizations of burnout that differ from that suggested by Maslach and adopted by the WHO. In 1999, Demerouti and Bakker, with their Oldenburg Burnout Inventory (OLBI), conceptualized burnout in terms of exhaustion and disengagement, linking it to the job demands-resources model. This instrument is used mainly in the United States. Also that year, Wilmar Schaufeli and Arnold Bakker released the Utrecht Work Engagement Scale (UWES). It uses a similar conceptualisation to the MBI. However the UWES measures vigour, dedication and absorption; positive counterparts to the values measured by the MBI. It is used mainly in Germany. In 2005, TS Kristensen et al. released the public domain Copenhagen Burnout Inventory (CBI). They argued that the definition of burnout should be limited to fatigue and exhaustion. The CBI has had