A newer generation of studies indicates that burnout, particularly its exhaustion dimension, problematically overlaps with depression; these studies have relied on more sophisticated statistical techniques, for example, exploratory structural equation modeling (ESEM) bifactor analysis, than earlier studies of the topic. The advantage of ESEM bifactor analysis, which combines the best features of exploratory and confirmatory factor analysis, is that it provides a granular look at item-construct relationships, without falling into traps earlier burnout researchers fell into.Liu and van Liew wrote that "the term burnout is used so frequently that it has lost much of its original meaning. As originally used, burnout meant a mild degree of stress-induced unhappiness. The solutions ranged from a vacation to a sabbatical. Ultimately, it was used to describe everything from fatigue to a major depression and now seems to have become an alternative word for depression, but with a less serious significance" (p. 434). The authors equate burnout with adjustment disorder with depressed mood. Kakiashvili et al., however, argued that although burnout and depression have overlapping symptoms, endocrine evidence suggests that the disorders biological bases are different. They argued that antidepressants should not be used by people with burnout because the medications can make the underlying hypothalamic–pituitary–adrenal axis dysfunction worse. Despite its name, depression with atypical features, which is seen in the above table, is not a rare form of depression. The cortisol profile in atypical depression, in contrast to that of melancholic depression, is similar to the cortisol profile found in burnout.
The rest cure was a commonly prescribed treatment (though there were many others). Beard yet further broadened the potential symptoms of neurasthenia over time, so that almost any symptom or behaviour could be deemed to be caused by it. Don R Lipsitt would later wonder if the term "burnout" was similarly too broadly defined to be useful.In 1961, Graham Greene published the novel A Burnt-Out Case, the story of an architect who became greatly fatigued by his work, and who took much time to recover.In 1969, HB Bradley used the term "burnout" in a criminology paper to describe the fatigued staff at a centre for treating young adult offenders. This has been cited as the first known academic work to use the term for this concept.In 1974, Herbert Freudenberger, an American psychologist, used the term in his academic paper "Staff Burn-Out." The paper was based on his qualitative observations of the volunteer staff (including himself) at a free clinic for drug addicts. He characterized burnout by a set of symptoms that includes exhaustion resulting from works 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 Freudenbergers paper, interest in the concept grew. In 1976, Christina Maslach noted the term being used by California lawyers working with the poor, and began to study the concept.In 1981, Maslach and Susan E. Jackson published an instrument for assessing burnout, the Maslach Burnout Inventory (MBI).