According to the World Health Organization (WHO),<unk>  is a syndrome resulting from chronic work-related stress, with symptoms characterized by "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". While<unk>  may influence health and can be a reason for people contacting health services, it is not itself classified by the WHO as a medical condition or mental disorder. The World Health Organization states that "Burn-out refers specifically to phenomena in the<unk>  context and should not be applied to describe experiences in other areas of life." In 1974, Herbert Freudenberger, an American psychologist, coined the term<unk> " and was the first researcher to publish in a scientific journal research on the syndrome. The paper was based on his observations of the volunteer staff (including himself) at a free clinic for drug addicts. He characterized<unk>  by a set of symptoms that includes exhaustion resulting from work's excessive demands as well as physical symptoms such as headaches and sleeplessness, "quickness to anger", and closed thinking. He observed that the burned-out worker "looks, acts, and seems depressed". After the publication of Freudenberger's original paper, interest in<unk>  grew. Because the phrase "burnt-out" was part of the title of the 1961 Graham Greene novel A Burnt-Out Case, which dealt with a doctor working in the Belgian Congo with patients who had leprosy, the phrase was likely in use outside the psychology literature before Freudenberger employed it. Wolfgang Kaskcha has written on the early documentation of the subject. Christina Maslach described<unk>  in terms of emotional exhaustion, depersonalization (treating clients, students, customers, or colleagues in a distant and/or cynical way), and reduced feelings of work-related personal accomplishment. In 1981, Maslach and Susan Jackson published an instrument for assessing<unk> , the Maslach<unk>  Inventory (MBI). It is the first such instrument of its kind and the most widely used<unk>  instrument. 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. The WHO adopted a conceptualization of<unk>  that is consistent with Maslach's, although the organization does not treat<unk>  as a mental disorder. Maslach advanced the idea that<unk>  should not be viewed as a depressive condition. Recent evidence, based on factor-analytic and meta-analytic findings, calls into question this supposition.
Occupational burnout
Idiopathic chronic fatigue
Social stress
Psychological resilience
Addiction vulnerability
Social isolation
Stress 
Computer addiction