The Autism Diagnosis Controversy: What Is Psychiatric 'Diagnostic Creep'?

In a conversation on the Lex Fridman podcast, psychiatric historian Andrew Scull examined the surge in autism diagnoses through the lens of a thought-provoking concept: "diagnostic creep." The discussion touches on one of the most contested issues in modern psychiatry — when the boundaries of a diagnosis keep expanding outward, are we discovering more genuine cases, or are we creating new patients?

What Is "Diagnostic Creep"?

The term "diagnostic creep" was coined by Australian scholar Nick Haslam, though Scull notes the phenomenon has played out repeatedly throughout the history of psychiatry. The logic works like this: a diagnostic category begins with a clear, unambiguous core — behaviors so severely deviant that any competent member of any culture would immediately recognize them as abnormal.

Then the boundaries begin to loosen. People argue that beyond this core lies a "penumbra" — individuals who are also affected, perhaps not severely enough to be clearly identified, but who are "genuinely experiencing something." So the diagnosis gradually expands outward, repeating this process again and again. This is one of the key mechanisms behind the dramatic rise in the number of psychiatric diagnoses.

Nick Haslam published a paper in 2016 systematically describing the phenomenon of "concept creep" — the finding that core psychological concepts (such as trauma, prejudice, and mental health) have steadily expanded over recent decades to encompass milder and broader manifestations. "Diagnostic creep" is a subset of this, referring specifically to the outward expansion of psychiatric diagnostic categories. This process is particularly visible across successive editions of the DSM (Diagnostic and Statistical Manual of Mental Disorders): from DSM-III to DSM-5, the number of diagnostic entries grew from 182 to over 300. Critics argue that this expansion partly reflects the pathologization of normal human experience, while supporters contend it represents long-overdue recognition of genuine suffering that was previously ignored. The tension between these two positions is precisely why "diagnostic creep" remains so controversial.

An Alternative Explanation for the Autism Diagnosis Surge

Scull draws on the perspective of Alan Frances, the lead editor of DSM-IV. Frances is convinced that the enormous growth in autism diagnoses is driven more by his own decision to loosen the diagnostic criteria than by any real increase in the number of actual cases. Autism was once a relatively rare condition; today it has become an umbrella category of sweeping breadth.

Scull acknowledges that he understands why parents of autistic children react strongly to this framing — because in practical terms, a diagnosis is a key. It unlocks access to social support, educational resources, and other forms of assistance. When a parent is raising an exceptionally difficult child to care for, the diagnosis itself is a ticket into the support system.

But he emphasizes that a real difference exists between the most severe forms of autism and milder cases. The former may leave individuals without language and unable to interact with others; the latter, while still serious, represents a far less severe presentation. Lumping both together under the same label risks obscuring that fundamental distinction.

DSM-IV was published in 1994 under Alan Frances's leadership, and was the first edition to incorporate Asperger's syndrome into the autism spectrum while lowering the overall diagnostic threshold for autism. Frances later publicly expressed regret in his book Saving Normal (2013), acknowledging that this revision was a key factor in the U.S. autism diagnosis rate skyrocketing from roughly 1 in 2,500 in the 1990s to approximately 1 in 36 in recent years. Nevertheless, the epidemiological community remains divided: some researchers argue that beyond the loosening of criteria, improved screening tools, greater public awareness, and incentives tied to special education funding are also important variables in the rising diagnosis rate. Whether the true prevalence has actually increased remains a matter of scientific debate.

Diagnostic Expansion Is Not Just "Psychiatric Imperialism"

A common misconception is to attribute the broadening of diagnostic categories entirely to psychiatry's appetite for expansion — so-called "psychiatric imperialism," the relentless pursuit of more territory and more patients. Scull argues this explanation is incomplete.

In reality, diagnostic creep is also driven by patients and the public themselves. When anyone attempts to tighten the criteria and push the boundaries back, they typically encounter fierce resistance. The reason is not hard to understand: diagnoses are tied to concrete benefits and support resources.

Scull specifically mentions organizations like NAMI (the National Alliance on Mental Illness). He makes the astute observation that the membership of these organizations consists not of people with mental illness themselves, but of their family members. Between family members and patients, there exists a difference in perspective and interests — a fact that is easily overlooked. Family members who push for diagnostic expansion are not necessarily acting in perfect alignment with the best interests of the patients themselves.

NAMI (National Alliance on Mental Illness) was founded in 1979, originally organized by the family members of people with mental illness — not the patients themselves. The organization has long been one of the most influential mental health advocacy groups in the United States, playing an important role in pushing the government to increase mental health resources and opposing the wave of psychiatric hospital closures. However, critics — including some participants in the "psychiatric survivor" movement — have argued that family-led advocacy can sometimes favor involuntary treatment and broader diagnoses over prioritizing patient autonomy. Scull's observation that "family organizations represent families" is not a dismissal of their value, but a reminder that when evaluating advocacy positions, we need to pay attention to the structural question of who is speaking on whose behalf.

The Most Solitary Affliction, the Most Social of Maladies

The conversation ends with a more humanistic insight. Scull quotes a line from his friend and fellow psychiatric historian Michael McDonald: mental illness is "the most solitary of afflictions for the sufferer and the most social of maladies for those around."

This phrase precisely captures the dual nature of mental health problems. For the patient bearing the suffering, it is a profoundly lonely experience; for those around them, it is a highly social one. For this reason, the effects of mental distress never remain confined to the patient — they radiate outward to everyone nearby.

This perspective also helps us understand why the question of diagnosis is so complex. A diagnosis is not merely a medical judgment — it sets in motion an entire web of relationships involving patients, families, educational systems, and social support structures. When we debate whether autism diagnostic criteria should be loosened or tightened, we are in fact weighing scientific rigor against the real-world needs of living people.

Conclusion

Scull's discussion offers no easy answers, but illuminates a genuine dilemma. Broadening diagnostic criteria may introduce the risk of overdiagnosis, yet tightening them could deprive many people of urgently needed support. Understanding the concept of "diagnostic creep" is not about dismissing anyone's suffering — it is about seeing more clearly the social forces and competing interests that shape psychiatric classification.