Defining and Evaluating Overdiagnosis in Mental Health: A Meta-Research Review

Background: Overdiagnosis is thought to be common in some mental disorders, but it has not been defined or examined systematically. Assessing overdiagnosis in mental health requires a consistently applied definition that differentiates overdiagnosis from other problems (e.g., misdiagnosis), as well as methods for quantification. Objectives: Our objectives were to (1) describe how the term “overdiagnosis” has been defined explicitly or implicitly in published articles on mental disorders, including usages consistent (overdefinition, overdetection) and inconsistent (misdiagnosis, false-positive test results, overtreatment, overtesting) with accepted definitions of overdiagnosis; and (2) identify examples of attempts to quantify overdiagnosis. Method: We searched PubMed through January 5, 2019. Articles on mental disorders, excluding neurocognitive disorders, were eligible if they used the term “overdiagnosis” in the title, abstract, or text. Results: We identified 164 eligible articles with 193 total explicit or implicit uses of the term “overdiagnosis.” Of 9 articles with an explicit definition, only one provided a definition that was partially consistent with accepted definitions. Of all uses, 11.4% were consistent, and 76.7% were related to misdiagnosis and thus inconsistent. No attempts to quantify the proportion of patients who were overdiagnosed based on overdetection or overdefinition were identified. Conclusions: There are few examples of mental health articles that describe overdiagnosis consistent with accepted definitions and no examples of quantifying overdiagnosis based on these definitions. A definition of overdiagnosis based on diagnostic criteria that include people with transient or mild symptoms not amenable to treatment (overdefinition) could be used to quantify the extent of overdiagnosis in mental disorders.