Criminalization of drug use in the United States has a detrimental effect on preventing HIV and treating the virus among injection drug users (IDUs), Newsweek reports.

Publishing their findings in The Lancet HIV, researchers conducted a literature review of 106 peer-reviewed studies published between 2006 and 2014 that focused on drug criminalization and HIV prevention or treatment among IDUs. Broken down by category of study, the review included 29 longitudinal (conducted with a group of participants over time), 49 cross-sectional (conducted at one time), 22 qualitative, two mixed-method and four mathematical-modeling studies.

The study authors identified 120 indicators of criminalization of drug use (each study focused on a range of one to three such indicators). Thirty-eight studies looked at incarceration, and 39 looked at street-level policing—the two most common criminalization indicators. The authors identified 150 indicators of HIV prevention and treatment, with a range of one to five per study. The most common such indicators were syringe sharing (35 studies) and prevalence of HIV among IDUs (28 studies).

Eighty-five of the studies (80 percent) suggested that criminalizing drug use is a detriment to HIV prevention and treatment efforts; 10 studies (9 percent) suggested no association between these factors; five studies (5 percent) suggested that drug criminalization had both null and negative effects on HIV prevention and treatment; five studies (5 percent) suggested a beneficial effect; and one study (1 percent) suggested both beneficial and negative effects. The latter six studies only ever showed a small benefit and were weak methodologically, according to the study authors.

The researchers concluded, “These data confirm that criminalization of drug use has a negative effect on HIV prevention and treatment. Our results provide an objective evidence base to support numerous international policy initiatives to reform legal and policy frameworks criminalizing drug use.”

To read a press release about the study, click here.

To read the Newsweek article, click here.

To read the study abstract, click here.