A recent study led by researchers from the University of Cambridge and the Metropolitan Police Service suggests that a significant number of individuals arrested in London may have undiagnosed attention-deficit/hyperactivity disorder (ADHD) or autism. The findings indicate that offering neurodivergence screening to people detained by police could improve access to support and lead to fairer treatment within the criminal justice system.
The research, published in Criminal Behaviour and Mental Health, involved voluntary screening at six London Metropolitan Police custody centres over an eight-week period in 2024. Of the 303 eligible detainees, 71% agreed to be screened for ADHD and autism using practical assessment tools designed to identify those who might benefit from further evaluation.
Dr. Tanya Procyshyn, a research associate at the Autism Research Centre at the University of Cambridge, stated: "To ensure fair treatment in the criminal justice system, we need to understand how neurodivergence affects interactions with the law. This can help avoid unnecessary criminalisation of misunderstood behaviour and ensure that potentially vulnerable individuals are able to access appropriate support."
The results showed that eight percent of those arrested had an existing ADHD diagnosis—higher than the estimated five percent prevalence in the general population. Additionally, half of those without a prior diagnosis met criteria suggesting possible undiagnosed ADHD. Seventeen percent had scores indicating a very high number of ADHD traits.
For autism, 4.2% reported an existing diagnosis, slightly above the three percent rate found in the general adult population. Another 5.4% screened positive for potential undiagnosed autism.
The study also noted that among those arrested for drug offences, 60% either had a diagnosis or screened positive for ADHD traits. Previous research has shown that some neurodivergent individuals may use illegal substances as a form of self-medication and that medication for ADHD can reduce criminal behaviour by improving impulse control.
Dion Brown, senior Detective from the Metropolitan Police Service and co-lead on the study, commented: "Screening for ADHD and autism at the first point of contact with law enforcement benefits both the criminal justice system and the individuals involved.
"Early identification helps officers interpret behaviours that might otherwise be misunderstood and ensures appropriate support is provided. This approach creates opportunities to divert vulnerable individuals away from the criminal justice process and towards the help they may need."
Professor Sir Simon Baron-Cohen, Director of Cambridge’s Autism Research Centre and member of the research team, added: "Screening for possible neurodivergence will allow more informed legal decision-making, taking into account cognitive and communicative differences. It can also help ensure defendants get access to legal protection and appropriate counsel. This could improve both the treatment and experiences of neurodivergent people in the criminal justice system and ultimately lead to fairer outcomes, including protection under the law, which is a basic human right."
The study was funded by the Wellcome Trust.
