Submitted by la334 on Wed, 17/12/2025 - 14:50
Offering routine screening for neurodivergence to people detained by police could improve access to support and lead to fairer treatment in the criminal justice system, according to researchers at the University of Cambridge.
A new study suggests that around one in two people arrested and detained in London may have undiagnosed attention-deficit/hyperactivity disorder (ADHD), while one in 20 may have undiagnosed autism.
Research has consistently shown that neurodivergent individuals—particularly autistic people and those with ADHD—are overrepresented in prison populations. However, estimates of how common these conditions are among people in contact with the criminal justice system have varied widely.
Dr Tanya Procyshyn, a research associate at the Autism Research Centre at the University of Cambridge, said:
“To ensure fair treatment in the criminal justice system, we need to understand how neurodivergence affects interactions with the law. This can help avoid the unnecessary criminalisation of misunderstood behaviour and ensure that potentially vulnerable individuals can access appropriate support.”
Dr Procyshyn co-led the study with Dion Brown, a senior detective with the Metropolitan Police Service. The research examined both the feasibility of screening detained individuals for ADHD and autism and the reasons leading to arrest.
Screening in police custody
Over an eight-week period in 2024, people detained at six Metropolitan Police custody centres in London were offered voluntary, on-site screening for ADHD and autistic traits. Screening was conducted by healthcare professionals, detention officers, or arresting police officers.
ADHD traits were assessed using a modified version of the Adult ADHD Self-Report Scale, while autistic traits were measured using the 10-item Autism-Spectrum Quotient. Although these tools are not diagnostic, they are widely used to identify individuals who may benefit from further clinical assessment.
The findings are published in Criminal Behaviour and Mental Health.
Of the 303 eligible individuals, 71% consented to screening. Those who scored above threshold were informed of their results and given guidance on how to pursue a formal diagnosis.
High levels of undiagnosed neurodivergence
Eight per cent of those screened reported an existing ADHD diagnosis—higher than the estimated 2.5% prevalence in the general population. However, a further 50% of individuals without a diagnosis screened positive for possible ADHD. Notably, 17% showed very high levels of ADHD traits.
Similarly, 4.2% of participants reported a prior autism diagnosis, compared with an estimated 1–2% prevalence in the general adult population. An additional 5.4% screened positive for possible undiagnosed autism.
The study also found a strong link between ADHD traits and certain types of arrest. Six in 10 people arrested for drug offences had either an existing ADHD diagnosis or screened positive for ADHD traits. Previous research suggests some neurodivergent individuals may use illegal substances to self-medicate, while medication for ADHD has been associated with reduced offending, possibly due to improved impulse control.
Implications for policing and justice
Dion Brown said:
“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 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 the Autism Research Centre at Cambridge and a member of the research team, added:
“Screening for possible neurodivergence enables more informed legal decision-making by taking cognitive and communicative differences into account. It also helps ensure defendants have access to legal protections and appropriate counsel. Ultimately, this could lead to fairer outcomes and better protection of basic human rights.”
The Wellcome Trust funded the research.
Reference
Brown, D. & Procyshyn, T. L. et al. (2025). Neurodiversity in custody: Screening results for ADHD and autistic traits in individuals arrested by the London Metropolitan Police. Criminal Behaviour and Mental Health. https://doi.org/10.1002/cbm.70018