Prison drug misuse is driving a crisis that now reaches well beyond prison walls. A new report from the National Audit Office (NAO) exposes the full scale of drug use in prisons across England and Wales, and the findings demand urgent attention.

Prison Drug Misuse: The Scale of the Problem

About 40,000 people had an identified drug problem as of April 2025. That is roughly half the entire prison population of England and Wales. The NAO report cites research showing that drug dependence rates among prisoners run many orders of magnitude higher than in the wider population. This is not a fringe issue. It sits at the centre of almost every failure the report identifies.

The damage spreads far beyond individual health. Drugs inside prisons fuel a hidden economy of debt, assault, extortion and self-harm. Gareth Davies, head of the NAO, put it plainly: substance abuse “undermines rehabilitation, damages health, and destabilises prison environments.”

An £88 Million NHS Bill

NHS England spends heavily on prison healthcare. The combined cost of substance misuse and mental health treatment in prisons reached £226.4 million in 2024 to 2025. NHS England attributes around £88.8 million of that directly to substance misuse. That is 39% of the total.

The source of that funding is also a concern. Prison healthcare teams now draw a growing share of their budgets from in-year bids to NHS England’s contingency reserves. Planned, ringfenced budgets are no longer covering the need. The system reacts rather than prepares.

Drug Use in Prisons Fuelled by Drones and Synthetic Substances

Smuggling methods have changed fast. Synthetic drugs are harder to detect and cheaper to produce. Drones carry them over prison walls with growing regularity. Between 2019 and 2023, reported drone sightings at prisons rose by more than 750%. Between April 2024 and March 2025, prisons in England and Wales recorded 1,712 drone incidents: a new peak.

This week, UK Defence Innovation launched a competition on behalf of the Ministry of Justice. It is looking for practical technologies to stop illegal drone use around prisons and other sensitive sites.

The human toll is not abstract. The Prisons and Probation Ombudsman investigated 833 prisoner deaths between December 2022 and December 2024. Drug-related causes accounted for 136 of those deaths: 16% of the total.

Prison Drug Misuse Is Getting Worse, Not Better

Security measures exist, but prison drug misuse continues to rise. In HM Inspectorate of Prisons surveys from 2024 to 2025, 39% of adult male prisoners said illicit drugs were easy to get. HMPPS recorded 26,348 individual drug finds in 2024 to 2025: a 25% rise on the previous year.

HMPPS has run mandatory random drug testing every month since 1999. That programme costs around £8 million a year. Yet 2017 to 2018 remains the last year the results counted as a robust national estimate. The testing infrastructure is there. It is not doing enough to shape treatment decisions.

Tackling Drug Use in Prisons Requires a Joined-Up Response

Restricting supply alone will not fix this. The NAO is clear: tackling prison drug misuse means combining strong security with genuine treatment and recovery programmes. Prisons also need environments that actively support drug-free living. That takes prison staff and healthcare providers working as a team.

At the moment, they are not. Prison staff say they lack real influence over health services. NHS staff say prison operations cut them out of key decisions, even though they rely on prison staff to do their jobs safely. This friction wastes money and puts lives at risk.

Davies summed up the failure: “Too many of the basic controls and interventions are not being done well enough, from repairing critical security equipment to aligning health and operational priorities.”

What Must Change Now

The NAO calls for action on several fronts. Security gaps that let drugs enter prisons need closing quickly. Testing data needs to feed directly into treatment planning. Prison services and health providers need to build stronger working relationships at both national and local level. And the government needs to evaluate which security and treatment measures work, and scale them up.

Prison drug misuse costs lives, drains NHS resources and blocks any real chance of rehabilitation. The evidence is on the table. What is needed now is the will to act on it.

By Dr Sheena Meredith | 5 February 2026

Source: dbrecoveryresources