Among opioid-dependent people in India who had been imprisoned, 65% used drugs during incarceration, with cannabis being the most commonly used substance inside prison at 35%.
Read this if you work in criminal justice, addiction treatment, or want to understand how incarceration affects substance use patterns.
65% used substances during incarceration; cannabis was most common (35%), overtaking opioids.
What the researchers found
Researchers surveyed 101 opioid-dependent people attending drug treatment clinics who had contact with the criminal justice system. Most (85%) had been imprisoned at least once, and drug use continued during incarceration at high rates.
Before imprisonment, opioids were the most commonly used daily substance (68%), followed by cannabis (34%) and alcohol (22%). Inside prison, the pattern shifted: cannabis became the most common substance (35%), followed by opioids (19%). This shift likely reflects differences in drug availability within prisons.
After release, 76% resumed substance use quickly, and 13% of opioid users experienced overdose soon after release, a well-documented period of heightened risk due to reduced tolerance.
Prior cannabis use, injection drug use, and opioid use before imprisonment all predicted continued substance use while incarcerated.
Why it matters
This study documents that incarceration does not stop substance use and that drug availability within prisons shapes which substances people use. The shift from opioids to cannabis during imprisonment, and the high rate of opioid overdose after release, highlights the need for evidence-based drug treatment within the criminal justice system rather than relying on incarceration as a deterrent.
The numbers in context
101 participants. 85% had been imprisoned. 65% used substances during imprisonment. Cannabis was most common in prison (35%), surpassing opioids (19%). 76% resumed use after release. 13% of opioid users experienced post-release overdose.
How the study worked
Cross-sectional study using purposive sampling of 101 opioid-dependent individuals attending two community drug treatment clinics in India. A specifically designed assessment tool recorded criminal acts and substance use patterns before, during, and after their last imprisonment.
What this study cannot tell us
This was a convenience sample from two clinics in India and may not represent all opioid-dependent incarcerated populations. Self-reported drug use during imprisonment may be underreported due to stigma and legal consequences. The cross-sectional design cannot establish causal relationships.
How to read the evidence
Preliminary evidence from a small cross-sectional study at two clinics in India. Useful for identifying patterns but limited by sample size and geographic specificity.
When this study was published
Published in 2016. The intersection of incarceration and substance use treatment continues to be debated globally.
The bigger picture
The transition from opioids to cannabis during incarceration suggests people adapt their substance use to what is available rather than stopping entirely. The high post-release overdose rate underscores that reduced tolerance during incarceration creates a life-threatening window when people return to opioid use at pre-incarceration doses.
Questions still open
- Does the shift to cannabis use in prison represent harm reduction compared to continued opioid use? Would providing medication-assisted treatment in Indian prisons reduce post-release overdose deaths? How do patterns of in-prison substance use differ across countries and prison systems?
Common questions
Do people stop using drugs in prison?
Why did cannabis replace opioids as the primary drug in prison?
Read the original research
Factors Affecting Drug Use During Incarceration: A Cross-Sectional Study of Opioid-Dependent Persons from India.
Journal of substance abuse treatment, 61, 13-7
Citation
Rao, Ravindra; Mandal, Piyali; Gupta, Rishab; Ramshankar, Prashanth; Mishra, Ashwani; Ambekar, Atul; Jhanjee, Sonali; Dhawan, Anju. (2016). Factors Affecting Drug Use During Incarceration: A Cross-Sectional Study of Opioid-Dependent Persons from India.. Journal of substance abuse treatment, 61, 13-7. https://doi.org/10.1016/j.jsat.2015.08.009
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