A large multi-centre study across 17 prisons in nine states in India has revealed widespread substance use among prisoners, exposing a public-health challenge within the country’s correctional system.
The study found that 51% of prisoners surveyed had consumed alcohol during their lifetime, nearly 20% had used cannabis and 11% had used opioids, underscoring the need for stronger addiction treatment and withdrawal care inside prisons.
The study, Prevalence of and factors associated with psychoactive substance use among people in prisons: A multi-centre, cross-sectional study in India, was led by researchers from the National Drug Dependence Treatment Centre (NDDTC), AIIMS, New Delhi, and involved experts from several leading institutions, including KGMU Lucknow, NIMHANS Bengaluru, Central Institute of Psychiatry, Ranchi, Government Medical College Chandigarh, Institute of Mental Health Hyderabad, RIMS Imphal, Assam Medical College, KEM Hospital Mumbai and SKIMS Srinagar.
The findings are significant not merely because of the prevalence of substance use but because they expose the vulnerability of a population that is already dependent on an overstretched prison healthcare system. At least 7,004 incarcerated people across the prisons were surveyed.
The study found that 51% of those surveyed had consumed alcohol during their lifetime, while nearly 20% had used cannabis and 11% had used opioids. A substantial proportion had used these substances shortly before entering prison.
Even during incarceration, 5.9% reported using a psychoactive substance. Cannabis accounted for 3.9% of reported use, followed by opioids at 1.8% and alcohol at 0.9%.
While these figures may appear considerably lower than lifetime-use estimates, researchers caution against interpreting them as evidence that substance dependence is insignificant inside prisons. The circumstances of incarceration, under-reporting and the availability of substances can all influence responses.
More importantly, the study identified groups particularly vulnerable to continued substance use in prison. Younger prisoners, repeat offenders and those who had consumed substances shortly before incarceration were at greater risk.
Previous cannabis use emerged as a particularly strong predictor. Prisoners who had used cannabis shortly before imprisonment were more than five times as likely to report substance use during their current incarceration, as per the study.
Withdrawal was another critical factor.
Those experiencing cannabis withdrawal had nearly three times higher odds of using substances during imprisonment. Opioid withdrawal was similarly associated with continued substance use, while alcohol withdrawal was also significantly linked to substance use during incarceration.
For Dr Ravindra Rao from the National Drug Dependence Treatment Centre, AIIMS, New Delhi, who led the study, these findings underline the need to look at substance dependence through a healthcare lens rather than treating it simply as a behavioural or disciplinary problem.
The study further said that issue becomes more urgent when the profile of the prison population is considered. Nearly 77% of those surveyed were first-time prisoners and about 65% were undertrials. The median duration of their current incarceration was nine months.
For a large section of the prison population, therefore, imprisonment is not a permanent condition but an interruption in their lives, after which they are expected to return to their families and communities.
“That makes prison healthcare an important opportunity for intervention,” said Dr Rao.
A particularly worrying finding concerns injecting drug use. About 4.3% of participants reported having injected drugs for recreational or non-medical purposes. Among those who had been injected, nearly half reported sharing injecting equipment, and 65% reported reusing it. Around 40% reported having experienced at least one overdose.
Some also reported testing positive for HIV or hepatitis C, underlining the wider public-health consequences of untreated substance dependence and unsafe injecting practices.
The implications extend beyond the prison walls. A person with untreated substance-use disorder may leave prison with the same dependency with which they entered. Interrupted treatment can increase the risk of relapse, overdose and other health complications after release, as per the study.
The researchers therefore called for systematic screening for substance-use disorders when prisoners enter correctional facilities. Those experiencing withdrawal need timely medical care, while individuals who were already receiving treatment before imprisonment should not have that care unnecessarily disrupted.
The study also pointed to the importance of opioid agonist treatment (OAT) within prisons. Such evidence-based treatment can reduce illicit opioid use and associated health risks and help improve the chances of sustained recovery.
Yet treatment inside prison alone will not be enough.
A prisoner beginning treatment during incarceration needs a clear pathway to addiction-care services after release. Without continuity between prison healthcare and community healthcare, an important opportunity for rehabilitation can be lost.
The findings also raise broader concerns about the very idea of prison healthcare. Correctional institutions are expected to maintain security and discipline, but they also hold people with complex physical and mental health needs. Addiction, infectious diseases, withdrawal, psychological distress and chronic illnesses cannot be addressed through confinement alone, said the researchers.
They emphasised that prison system therefore needs a stronger public-health architecture, including trained medical personnel, confidential screening, evidence-based addiction treatment, mental-health services and mechanisms for referral after release.
At the same time, they said, the study should not be read as a national prevalence estimate.
It was a cross-sectional study, was not nationally representative and relied on self-reported substance use rather than biological testing.
Nevertheless, its large sample and geographical spread across 17 prisons provide valuable evidence of a problem that has received relatively little attention.
The larger concern is what happens to people whose addiction remains untreated.
The researchers concluded that addiction behind bars cannot be addressed simply by preventing access to substances. It requires identifying dependence, managing withdrawal safely, providing treatment and ensuring rehabilitation.
