By Daisy Yuhas for Spectrum – February 2019

Autism and obsessive-compulsive disorder frequently accompany each other; scientists are studying both to understand how they differ.

Steve Slavin was 48 years old when a visit to a psychologist’s office sent him down an unexpected path.

At the time, he was a father of two with a career in the music industry, composing scores for advertisements and chart toppers.

But he was having a difficult year.

He had fewer clients than usual, his mother had been diagnosed with cancer, and he was battling anxiety and depression, leading him to shutter his recording studio.

Slavin’s anxiety — which often manifested as negative thoughts and routines characteristic of obsessive-compulsive disorder (OCD) — was nothing new.

As a child, he had often felt compelled to swallow an even number of times before entering a room, or to swallow and count — one foot in the air — to four, six or eight before stepping on a paving stone.

As an adult, he frequently became distressed in crowds, and he washed his hands over and over to avoid being contaminated by other people’s germs or personalities.

His depression, too, was familiar — and had caused him to withdraw from friends and colleagues.

This time, as Slavin’s depression and anxiety worsened, his doctor referred him to a psychologist.

“I had had an appointment booked for weeks and weeks and months,” he recalls.

But about 10 minutes into his first session, the psychologist suddenly changed course: Instead of continuing to ask him about his childhood or existing mental-health issues, she wanted to know whether anyone had ever talked to him about autism.

By coincidence, a relative had mentioned autism to Slavin two days prior, wondering if it might explain why he dislikes social situations.

Slavin knew little about the condition but had conceded it was possible.

By the time his therapy session ended, his psychologist was almost certain: “She said to me that I’ve either got high-functioning autism or some kind of brain damage,” Slavin recalls with a chuckle.

Only a few years earlier, a doctor had finally diagnosed him with OCD.

His new psychologist diagnosed him with autism as well.

Part of that overlap may reflect misdiagnoses: OCD rituals can resemble the repetitive behaviours common in autism, and vice versa.

But it’s increasingly evident that many people, like Slavin, have both conditions.

People with autism are twice as likely as those without to be diagnosed with OCD later in life, according to a 2015 study that tracked the health records of nearly 3.4 million people in Denmark over 18 years.

Similarly, people with OCD are four times as likely as typical individuals to later be diagnosed with autism, according to the same study.

This story was originally published on Spectrum. For the remainder of the story go to Spectrum.