“The DSM (Diagnostic and Statistical Manual of Mental Disorders) wants us to believe — and of course, I don’t mean to be flippant, the founder or the people who write these diagnostic categories, they believe — that there are distinct unchanging categories of mental disorders. That’s not what the data say. The dimensionality of psychological problems makes us question the binary yes/no categories, but it’s also very important in terms of [reducing social] stigma [about seeking help for one’s difficulties].

“In a dimensional approach, there’s no hard line between normal and abnormal. There’s no hard line between normal and ill, to be sure. A person doesn’t need to think, ‘I might be mentally ill’ to go and seek help, to go and ask if there’s something that can be done to make [their] life happier and more functional. They simply, in a dimensional approach, have to say, ‘there are things about my behavior that just aren’t working. I want to go see if I can get some help.’

“Just like if you’re a tennis player, and you are now serving the ball consistently into the net and you just can’t get it right, you don’t have to call up your tennis pro and say, ‘I’ve fallen into the abyss of mental illness and I need your help.’ You just say, ‘hey, something about my game isn’t working. Can you look at it? Talk to me about things that I can do to make it more functional for me.’

“And so that game can be the game of life. We can go in and seek help in a way that doesn’t require admitting that we’re no longer like every other human being.”

— from Lahey, B., & Sharp, J. (2021, August). 226. Dimensional conceptualization of psychological problems w/ Dr. Ben Lahey. The Testing Psychologist Podcast.

Lahey, B. B. (2021). Dimensions of psychological problems: Replacing diagnostic categories with a more science-based and less stigmatizing alternative. Oxford University Press.

I hope that diagnosis will be no longer considered a “dirty word” (quoting Nancy McWilliams), or a bureaucratic or devalued act. Rather, it is an engaging and challenging process that can bring us back to the original, ancient meaning of the word diagnosis: “knowing through.” Through the patient, dialogue, and relationship.

The diagnostic process has no simple, easily applied formula. In his General Psychopathology (1913), Karl Jaspers claims that “Every diagnostic schema must remain a tiresome problem for the scientist” (Alle Diagnosenschemata müssen für den Forscher eine Qual Bleiben). In the original quote, the German word Qual is used where “tiresome” has been used here; Qual literally means “torment,” and in fact I think that for researchers and clinicians diagnosis should be a “torment.”

There is always a tension between the need to connect a patient to a general category and, at the same time, to connect the patient to [their] unique qualities — “the impossible science of the unique being,” as Roland Barthes would say.

from Featured Author – Vittorio Lingiardi. (2017, December). Guilford Press.

The evidence indicates that clinicians who use a single method to obtain patient information regularly draw faulty conclusions.

For instance, Fennig, Craig, Tanenberg-Karant, and Bromet (1994) reviewed the diagnoses assigned to 223 patients as part of usual hospital practice. Clinical diagnoses were then compared with diagnoses derived from a comprehensive multi-method assessment that consisted of a semistructured patient interview, a review of the patient’s medical record, a semistructured interview with the treating clinician, and an interview with the patient’s significant other, all of which were then reviewed and synthesized by two clinicians to derive final diagnoses from the multi-method assessment.

Even though Fennig, Craig, Tanenberg-Karant, et al. (1994) used very liberal criteria to define diagnostic agreement (e.g., major depression with psychotic features was treated as equivalent to dysthymia), the diagnoses assigned during the course of typical clinical practice had poor agreement with the diagnostic formulations derived from the more extensive synthesis of multiple assessment methods.

Overall, after discounting chance agreement, the clinical diagnoses agreed with the multi-method conclusions only about 45-50% of the time. This was true for a range of disorders on the schizophrenic, bipolar, and depressive spectrums.

Because these conditions are treated in decidedly different ways, such frequent misdiagnoses in typical practice suggest that many patients erroneously receive antipsychotic, antimanic, and antidepressant medications.

from Meyer, G. J., Finn, S. E., Eyde, L. D., Kay, G. G., Moreland, K. L., Dies, R. R., Eisman, E. J., Kubiszyn, T. W., & Reed, G. M. (2001). Psychological testing and psychological assessment. A review of evidence and issues. The American Psychologist, 56(2), 128–165.