A few decades ago, after graduating from medical school, I learned that autism was considered to be a rare disorder. Textbooks would report a prevalence of 1 in 10,000 individuals.  Indeed, I remember one of my basic neurology textbooks stating that specialists would probably get to see 1 or 2 cases throughout the life of their clinical practice.  I am not that old, I graduated from medical school in the late 1970s. Those medical textbooks were written some 30 years after Kanner’s introduced the term to the literature.  Still, a diagnosis of autism remained invisible to many clinicians.  What was happening?

It is noteworthy that by the time of my medical school graduation, I had already seen a couple of cases of childhood schizophrenia.  Such encounters were not considered uncommon.  I remember reading some of the patient series and accounts from Lauretta Bender in which she talked about her series; an experience of thousands of childhood schizophrenia cases. Bender was the psychiatrist who lent her name to the now famous Bender-Gestalt test.  She was trained over at the Johns Hopkins Hospital before moving to New York and making her career at  the Bellevue Hospital.  During her lifetime, Bender was considered a force of nature.  Other physicians would bow to her and defer to her opinion as dogma.  This was rather unfortunate as many of her patients could easily have been considered autistics under modern diagnostic criteria.  Even more unfortunate was the fact that Bender would use extreme measures in many of her patients as possible therapeutic interventions.  This included the use of insulin shock therapy as a way of resetting the brain.  Back then, Internal Review Boards (IRB) were not set in hospitals and patients were truly the guinea pigs of clinicians.

It really took somebody of courage to step up in the international arena and challenge the views of Bender.  That brave soul was Leo Kanner.  His debate with Bender was a respectful disagreement that transpired within the medical literature but never got personal.  Both individuals knew each other from their training days at the Johns Hopkins Hospital and Bender even wrote one of the obituaries praising Kanner upon his death.  In spite of their friendship, their disagreement ran for decades. The main objection for Kanner was that autism was a developmental condition; patients were born autistic! This trajectory differed markedly from schizophrenics that, according to Kanner, acquired and manifested symptoms sometime after birth.  Curiously, this was the same reasoning that separated Kanner from Asperger in their case series.  Asperger also believed that symptoms were acquired after birth, as a personality disorder.

Throughout the years the distinction between childhood schizophrenia and autism has remained fraught in controversy.  Mice with a mutation of the Shank3 gene may serve as models for schizophrenia or autism depending on the type/location of mutation.  Also, for some cases, catastrophic events may propitiate the expression of symptoms in both of these conditions.  This is a well-known phenomenon in schizophrenia where many young individuals would exhibit full blown symptoms after leaving their social safeguards in order to go to college or army basic training. In autism, the same phenomenon has only recently received attention by clinicians.  As part of the diagnostic criteria of DMS 5 we now stipulate that some autistic patients may develop their symptoms only after social exigencies overwhelm the patient.

In one of my series, from a state hospital in KY, a significant number of elderly patients who had been admitted as childhood schizophrenia patients had their diagnosis revised to autism.  This series had some 10 patients the youngest of which was about 49 years of age.  Unfortunately, institutionalization in these cases had grave consequences and many had lost a majority of their previous cognitive abilities.  However, it clearly illustrated to me that autistic patients were present, albeit remaining invisible to diagnosis, for many decades.  In this regard, one of many possible explanations to the rise on prevalence of autism is diagnostic substitution.  Many patients previously diagnosed with childhood schizophrenia were truly autistic.

References

An article expanding on the shared symptoms and pathology between schizophrenia and autism: de Lacy N, King BH. Revisiting the relationship between autism and schizophrenia: toward an integrated neurobiology. Annu Rev Clin Psychol. 2013;9:555–587. [PubMed] [Google Scholar]

Stone WS, Iguchi L. Do apparent overlaps between schizophrenia nad autism spectrum disorders reflect superficial similarities or etiological commonalities? N am J Med Sci 4(3):124-133, 2011.