The latest definition, in WHO’s International Classification of Diseases (ICD-11), says: “Burn-out is a syndrome conceptualized as resulting from chronic workplace stress that has not been successfully managed. It is characterised by three dimensions:

• feelings of energy depletion or exhaustion
• increased mental distance from one’s job, or feelings of negativism or cynicism related to one's job, and
• reduced professional efficacy. Burn-out refers specifically to phenomena in the occupational context and should not be applied to describe experiences in other areas of life.”

Burnout’s changed status generated considerable press coverage. Some media outlets incorrectly reported that burnout is classified as a disease in ICD-11, apparently because of an incorrect communication issued by the WHO, which it later corrected.

While ICD-11 does not classify burnout as a medical condition, it has been designated as a syndrome. A syndrome is a collection of signs and symptoms associated with a specific health-related cause.

The previous classification, in ICD-10, simply defined burnout as a “state of vital exhaustion”.

The European Trade Union Institute said it was a “landmark decision … opening the door to having it classified in the WHO's International Classification of Diseases” – ie making it a diagnosable medical condition.

From factor to disease

Other conditions have made a similar journey from a health-influencing factor to a disease entity.

Osteoporosis was once considered an unavoidable part of normal ageing and was listed as a factor influencing health status or contact with health services.

It became a disease in 1994 when it was classified under diseases of the musculoskeletal system and connective tissue.

Prospect health and safety officer Chris Warburton said: “There are positive elements to the new classification. It is welcome that burnout will be explicitly linked to the workplace and it could well bring increased attention to the issue.

“The current classification, under problems associated with life-management, individualises the issue.

“The significantly expanded definition will be useful for identifying problems and, hopefully, addressing them in the workplace.

“However, there are reasons to be cautious. There is a risk is that normal human emotional states are treated as illnesses and the social causes of the distress overlooked.”

Warburton pointed to the academic and bioethicist Erik Parens who said that “as medicine focuses on changing individuals’ bodies to reduce suffering, its increasing influence steals attention and resources away from changing the social structures and expectations that can produce such suffering in the first place”.

ICD is a classification standard that defines all diseases, disorders, injuries and other related health conditions.

It is used for statistical research purposes and as diagnostic assistance. ICD lists conditions in a hierarchical manner, with similar conditions clustered together.

ICD-11 will come into force on 1 January 2022.