Despite the aforementioned criticisms, many still consider burnout to be meaningfully distinct from depression. For instance, Epstein and Privitera [94] argued that, although evidence supports the presence of substantial overlap between both constructs, workers do not always simultaneously experience burnout and depression. They further highlight that, relative to depression, burnout cannot be considered a purely individual syndrome because it is intimately related to a “breakdown in the relationship between people and their work” [94] (p. 1). From a practical perspective, they note that conceptualizing burnout as depression would stigmatize the struggles of many employees from occupational groups particularly affected by burnout (e.g., physicians) as an individual issue, rather than properly contextualizing their distress within a problematic systemic or institutional setting [94]. To address these concerns, Bianchi et al. [32] noted that the reliance on a measure of depression specific to work would make it possible to retain these contextual considerations. However, this recommendation relies on the assumption that burnout and depression are empirically indistinguishable phenomena.

In a meta-analysis of research published between 2007 and 2018 to examine the overlap between burnout, depression, and anxiety, Koutsimani et al. [89] noted that, although there was indeed evidence of overlap between burnout, depression, and anxiety, the bulk of the results still supported the distinctive nature of these three psychological states. Interestingly, they also found that studies using the Maslach Burnout Inventory (MBI) tended to demonstrate cleaner distinctions between the constructs relative to those relying on other measures of burnout. The distinction between burnout and depression has also been supported by various factor analytic studies supporting the idea that both constructs retain a meaningful amount of specificity once their common core is considered [63,64,87]. There is also qualitative evidence for the distinctive nature of burnout and depression. For instance, Tavella and Parker [95] recruited 1019 workers who self-reported having experienced both depression and burnout. These workers completed an open-ended questionnaire recording the symptoms they attributed to burnout, the main cause of their symptoms, and how they differentiated between burnout and depression symptoms. Their qualitative analyses revealed that several themes contributed to differentiate burnout from depression. Thus, whereas participants were able to ascribe a clear external cause to their symptoms of burnout, they had a more challenging time identifying the causes of their depression, which seemed to be more intrinsically rooted. Participants also reported that burnout was associated with higher functioning, greater self-esteem, less suicidal ideation, and more hope than depression. Additionally, participants reported that burnout felt more like an anxious and activated state than depression, which was characterized by feelings of heaviness and slowness. The presence of anhedonia in depression, but not in burnout, was another major distinction. Finally, approximately one-fifth of the participants could not distinguish depression from burnout, with some noting that their experience of burnout led to depression.

Lastly, in a recent longitudinal investigation of the reciprocal associations between burnout and depression, Tóth-Király et al. [92] found evidence supporting the discriminant validity of both constructs. First, they demonstrated that while burnout was an inherently multidimensional construct, depression was better conceptualized as a unidimensional phenomenon. Second, although both constructs were found to be reciprocally related both within and over time, their associations remained moderate in magnitude, consistent with the presence of variability uniquely associated with both constructs. Lastly, they found evidence that both constructs shared a well-differentiated pattern of association with a series of theoretically relevant covariates.

To summarize the previous discussion, current theoretical considerations and empirical results can be leveraged to support both the notion that burnout is distinct from depression and that these two psychological phenomena share substantial conceptual overlap. Based on this conflicting evidence, some researchers argue that burnout is simply work-specific depression and should be studied as such [13,77,88,96], whereas other argue that both represent theoretically and empirically distinct psychological constructs [89,92,97,98]. Nonetheless, while the burnout–depression debate is an important and pervasive one, it is not the only consideration from a diagnostic perspective. To determine whether burnout should or could conceivably be characterized as a mental disorder, burnout must also be evaluated within the context of current diagnostic classification models. This examination might help us to devise the next steps in a research program that could also prove helpful in clarifying the burnout–depression debate.

In and of itself, the debate surrounding the classification of burnout as a diagnosable condition is not new. Though no universally agreed-upon definition of burnout exists and though burnout has not yet been formally incorporated in any existing diagnostic classification systems, researchers and clinicians have been classifying and “diagnosing” burnout as a syndrome for years [82]. This may be related, at least in part, to the fact that in the early days of burnout research, Maslach et al. [99] included cut-off scores in the MBI test manual to help identify clinically significant levels of burnout. Thus, although the MBI was explicitly designed as a continuous measure of burnout severity, these cut-off scores sparked a surge of studies in which employees were classified based on the severity of their symptoms. Additionally, because accumulated research evidence supports the clinical validity and utility of the MBI, some researchers have concluded that it was therefore suitable as a diagnostic tool [49,100]. However, measures of burnout rely predominantly, if not exclusively, on self-report. This is, and has always been, a considerable limitation of psychological or psychiatric diagnoses, which cannot be established in the absence of additional signs of health and behavior typically collected via clinical interviews [21]. One last consideration comes from the more practical considerations of health professionals, whose clinical services are typically more easily reimbursed by governmental agencies or insurance companies when there are linked to diagnosable medical conditions [3].

Nowadays, several European countries acknowledge burnout as a legitimate mental disorder. Lastovkova et al. [14] and Guseva Canu et al. [101] contrasted burnout classifications and found that it is acknowledged as an occupational disease in 14 European countries but is only officially listed as an occupational disease in Latvia. In five European countries, it is common practice to grant workers suffering from burnout with financial compensation. In Iceland, the Netherlands, and Sweden, if one can prove causality related to work conditions, any illness or injury can be classified as an occupational disease, including burnout [14,101]. The Netherlands is currently the only country using the MBI as a clinically validated diagnostic tool, issued by the Royal Dutch Medical Association as a strategy to manage stress-related disorders [102]. Diagnostic criteria vary widely by country, with most criteria derived from regional or national committees [14,101]. Thus, although burnout is a common diagnosis in Europe, there is currently no consensus surrounding financial compensation, diagnostic criteria or protocols, and the role of work-related and individual determinants in the etiology of burnout [101].