A landmark study into London’s criminal justice system has revealed that an unexpectedly high proportion of people arrested in the capital may have undiagnosed attention deficit hyperactivity disorder (ADHD),raising urgent questions about how the police,courts and prisons deal with neurodivergent individuals. Drawing on data from thousands of cases, the research suggests that ADHD-already under-identified in the general population-could be dramatically more prevalent among suspects than previously assumed. The findings are fuelling calls for routine screening, better mental health support in custody, and a fundamental rethink of how Britain addresses the overlap between neurodevelopmental disorders and crime.
ADHD prevalence among arrested individuals in London challenges traditional views on crime
The sheer proportion of suspects in the capital who show signs of attention deficit hyperactivity disorder is forcing criminologists and policymakers to rethink long‑held assumptions about why people offend. Instead of a simple narrative of “bad choices” and “hardened criminals,” emerging evidence suggests that for many, impulsivity, poor emotional regulation and chronic restlessness – hallmarks of the condition – may be powerful drivers of risky behavior. This raises uncomfortable questions for a justice system built on the idea of rational decision‑making, where intent is judged without routinely considering neurodevelopmental disorders that can distort judgment in the heat of the moment.
Researchers and frontline practitioners say the implications are far‑reaching for policing, courts and rehabilitation. If a considerable share of those cycling through custody suites have undiagnosed or unmanaged ADHD, then traditional punitive responses may be targeting symptoms rather than causes, and missing chances to interrupt a revolving door of arrest, release and reoffending. That is prompting calls for a new toolkit inside London’s criminal justice institutions, including:
- Routine screening for neurodevelopmental conditions at the point of arrest.
- Specialist training for officers, magistrates and probation staff on how ADHD shapes behaviour.
- Treatment pathways that link suspects swiftly to clinical assessment and tailored support.
- Rehabilitation programmes redesigned to account for attention, memory and impulse‑control difficulties.
| Aspect | Traditional view | ADHD-informed view |
|---|---|---|
| Cause of offending | Moral failure | Neurodevelopment + environment |
| Response | Punishment | Treatment & support |
| Goal | Deterrence | Reduced reoffending |
How undiagnosed neurodivergence distorts justice outcomes from police custody to prison
Once a person with undiagnosed ADHD enters the system, every stage from interview room to sentencing quietly amplifies their difficulties. In police custody, rapid-fire questions, fluorescent lights and long waits collide with impulsivity, sensory overload and poor working memory. Officers may misinterpret fidgeting, rapid speech or inconsistent answers as guilt or deceit rather than symptoms.This mismatch often leads to:
- False assumptions of non-cooperation when someone can’t follow complex instructions.
- Missed chances for diversion as screening tools are rarely used at booking.
- Risky “confessions” from people eager to end a stressful interview, not to accurately recount events.
| Stage | Typical Response | How ADHD Is Misread |
|---|---|---|
| Custody | Restless, overwhelmed | Seen as aggression |
| Court | Distracted, interrupting | Judged as disrespectful |
| Prison | Rule-breaking, impulsive | Labeled “chronic troublemaker” |
That initial misreading follows people into court and then behind bars. In hearings, difficulty sitting still, tracking legal jargon or waiting to speak can be taken as a lack of remorse, influencing bail decisions and sentence length.Inside prison, the same traits magnify: missed medication, rigid regimes and constant noise clash with poor impulse control and time management, driving up infractions and solitary confinement. As a result, people with unrecognised ADHD are more likely to:
- Receive longer sentences due to perceived non-compliance with court and probation demands.
- Lose access to rehabilitation programmes as of disciplinary records rooted in untreated symptoms.
- Leave custody with no diagnosis, no treatment plan and a heightened risk of reoffending.
Inside the gaps in mental health screening that leave vulnerable suspects without support
At the heart of the problem is a fast-paced, high-pressure custody process that was never designed to pick up nuanced neurodevelopmental conditions. Screening relies heavily on brief questionnaires, rushed observations and a suspect’s own self-disclosure – a flawed approach when many people with ADHD, autism or learning difficulties may not have a formal diagnosis, or may struggle to articulate what they need. Frontline officers and custody staff often receive minimal training on spotting less obvious behavioural cues, meaning that signs such as agitation, impulsive speech or difficulty following instructions are misread as simple non-compliance or defiance. In this environment, the default response is usually control and containment, not clinical curiosity.
- Time-limited assessments that prioritise risk over neurodiversity
- Patchy access to mental health professionals in custody suites
- Inconsistent recording of suspected or self-reported conditions
- No clear pathway from arrest to specialist ADHD evaluation
| Stage | What should happen | What often happens |
|---|---|---|
| Arrival in custody | Structured mental health triage | Basic risk checklist only |
| Health screening | Neurodiversity-specific questions | Focus on self-harm, substance use |
| Ongoing detention | Access to specialist assessment | Observation without follow-up |
For suspects with untreated ADHD, the consequences are stark: without recognition or adjustments, they may appear more volatile in interviews, struggle to follow legal advice, and inadvertently undermine their own defense.Solicitors report clients who cannot sit still through questioning, forget crucial details or interrupt proceedings out of sheer restlessness rather than disrespect. Yet these behaviours rarely trigger a referral for further assessment. The result is a quiet but systemic failure in which neurodivergent people move through the criminal justice system classified as “difficult” rather than “in need of support”, reinforcing a cycle of reoffending that targeted screening and early intervention might otherwise begin to break.
Policy shifts and practical reforms experts say could cut reoffending and improve public safety
Specialists argue that the London figures make a powerful case for moving from a purely punitive model towards one that embeds neurodevelopmental screening and treatment into the justice system. They are calling for routine ADHD assessments at first police contact, diversion into tailored health services for suitable cases and a dramatic expansion of prison-based mental health teams. Under their vision, officers would be trained to recognise symptoms such as impulsivity, emotional dysregulation and poor concentration, while courts would gain access to rapid diagnostic reports to inform sentencing. The emphasis, they say, is on cutting the cycle of arrest, release and rearrest by addressing the root causes of chaotic behaviour rather than simply warehousing people in overcrowded cells.
- Mandatory screening at custody suites and probation intake
- Fast-track clinics for ADHD assessment and medication review
- Trauma-informed staff training for police, prison and court personnel
- Integrated care plans linking prisons, NHS and community services
- Data sharing safeguards to protect rights while tracking outcomes
| Reform | Main Goal |
|---|---|
| ADHD screening at arrest | Early identification |
| Health-led diversion schemes | Fewer first-time custodial sentences |
| Prison treatment programmes | Stabilise behaviour inside |
| Post-release support | Reduce reoffending risk |
Evidence from pilots in England and abroad suggests these changes can deliver measurable public safety gains. Studies cited by clinicians show that effective ADHD treatment is associated with lower rates of violent incidents in custody, improved compliance with probation conditions and fewer emergency police call-outs. Criminologists caution that medication alone is not a cure-all, but say that when it is combined with stable housing, employment support and cognitive-behavioural programmes adapted for people with attention and impulse-control difficulties, reoffending can fall sharply. For cash-strapped justice agencies, the economic argument is also compelling: experts estimate that investing in specialist assessment units and community follow-up could cost far less than the price of repeated prosecutions and prison terms that fail to change behaviour.
Key Takeaways
As police forces and policymakers grapple with the findings, the study raises a fundamental question about how Britain deals with both crime and neurodiversity. If large numbers of people entering the justice system are living with undiagnosed ADHD, the issue is no longer solely one of individual obligation, but of institutional blind spots.
For campaigners, the hope is that this research will mark a turning point: away from a model that waits to punish people once they have fallen through the cracks, and towards one that identifies and supports vulnerable individuals much earlier. Whether the government, courts and prisons act on that evidence – and whether they are prepared to invest in assessment, treatment and training – may determine if these numbers remain a stark statistic, or become the basis for lasting reform.
