Abstract
I define psychiatric “overdiagnosis” as the observation that there has been a rapid rise in the rate of mental health diagnoses in recent decades, combined with the suspicion that a substantial proportion of these diagnoses are illegitimate or unwarranted. I propose that a major and under-recognized contributor to both the rise and the suspicion is diagnostic stretching: the application of a specified diagnostic category to a presentation that does not meet its official criteria but is accompanied by clinically significant distress or impairment, to make that presentation legible to the institutions that organize care. Since the 1990s, specified categories such as major depressive disorder, ADHD, bipolar disorder, and autism have been stretched in clinical practice to cover patients who have the relevant symptoms and clinically significant distress or impairment but whose presentations are subthreshold or phenomenologically adjacent. Increased awareness of mental health problems has lowered the help-seeking threshold, so that the population that comes to clinical attention is converging on the population that meets a burden threshold independent of help-seeking. Stretching is a response to genuine clinical need interacting with official classifications that are too narrow, not too broad. The overdiagnosis backlash correctly perceives a mismatch between official criteria and diagnostic practice but misidentifies its source, reading as laxity what is better understood as unmet need routed through official categories that are not adequate to the task.