A patient sits in the waiting room of a doctor's office.
Unexpected delays: Missed diagnoses or misdiagnoses in childhood may explain the high incidence of psychiatric co-morbidities in autistic people identified in adulthood.
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Autism diagnosis in adulthood tied to increased burden of psychiatric conditions

Mood, anxiety, personality and eating disorders more commonly affect autistic people diagnosed in adulthood than those diagnosed in childhood.

People diagnosed with autism in adulthood are nearly three times as likely as their childhood-diagnosed counterparts to report having psychiatric conditions, a new study finds.

“Experiences of childhood- versus adulthood-diagnosed people are likely to be quite different,” says lead investigator Vanessa Bal, Karmazin and Lillard Chair in Adult Autism at Rutgers University in Piscataway, New Jersey. Generalizing findings from one group to the other “is going to have serious implications for research.”

The substantial differences between these groups suggest “studies reporting outcomes for adults with autism are now incomplete in their conclusions if we do not know when the diagnosis was made,” says Eric Butter, chief of the psychology section at Nationwide Children’s in Columbus, Ohio, and director of the hospital’s Child Development Center. Butter was not involved in the study.

Increasingly, studies of autistic adults involve people identified later in life, in part because of expanded diagnostic criteria for the condition and online surveys that make it easy for participants who live far from the researchers to join in. But little is known about how these adults compare with those identified as autistic earlier in life.

The new study drew on data from 4,657 legally independent autistic adults — including 2,826 women — from the Simons Powering Autism Research Knowledge (SPARK) project. (SPARK is funded by the Simons Foundation, Spectrum’s parent organization.)

The 2,210 participants diagnosed with autism at age 21 or older were 2.7 times more likely to report co-occurring mood, anxiety, personality or eating disorders than those identified with autism in childhood, the researchers found. Adulthood-diagnosed people also reported more lifetime psychiatric conditions: an average of 3.2, versus 2.8 in their childhood-diagnosed peers.

“We don’t know if this is due to their being misdiagnosed with other conditions, or whether those diagnoses — for example, anxiety, depression — may be the effects of living without a proper autism diagnosis throughout childhood, adolescence and beyond,” Bal says. “Probably both are factors.”

The findings suggest diagnostic tools and processes need improvement to enable earlier diagnoses for autistic people with co-occurring mental health conditions, says Micah Mazurek, Novartis U.S. Foundation Professor of Education at the University of Virginia at Charlottesville, who was not involved in the work..

“When children or adolescents don’t receive a timely diagnosis, they miss opportunities for appropriate services and supports that are tailored to their unique needs,” Mazurek says. “They also miss out on opportunities to build self-understanding and connections within the autism community, placing them at greater risk for negative mental health outcomes.”

T

he study supports previous work that uncovered a high prevalence of psychiatric conditions among autistic adults in general. As a whole, those in the new analysis have three psychiatric conditions, on average, with women being 1.7 times more likely than men to have co-occurring conditions such as eating, anxiety and affective disorders.

The results, published 29 August in Autism Research, underscore “the mental health crisis facing autistic adults,” Bal says. More autism training is needed for all mental health fields at all levels — and not just in pediatric care, but in adult care too, she notes.

“There is a shortage of mental health clinicians adequately trained to provide supports for autistic adults — many providers report lower feelings of competence and are reluctant to take autistic adults as clients,” Bal says. Autism is often viewed “as a specialty field, and it is not well-integrated in assessment or treatment training.”

Mazurek agrees that there is a “critical need for mental health professionals who are equipped to meet the needs of autistic adults,” noting that more than 80 percent of the new study’s participants “had a history of some type of mental health disorder.”

Butter adds that “there may be a tendency among some clinical providers and autistic adults recently diagnosed to reframe struggles and adjustment difficulties as solely being rooted in autism, or to minimize co-occurring signs and symptoms of other psychological impairments in light of a recent diagnosis.” He stresses that “access to treatment for co-occurring conditions should be a priority even after a diagnosis with autism spectrum disorder has been made.”

It remains uncertain whether these findings apply to autistic adults in general, Bal notes, in part because the entire study sample comes from North America, is almost 70 percent white and includes more women than men. The results need to be replicated in more diverse samples, and ideally in groups in which researchers can note the timing of psychiatric diagnoses to see whether and how a misdiagnosis or missed diagnosis of autism might drive these problems, she says.

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