Major surveys on drug use in the U.S. may reflect less about drug use trends than about the willingness of survey participants to disclose their drug use, a new report says.

Medical News Today Medical News Today reported March 6 that researchers from the National Development and Research Institutes examined drug-use data gathered as part of the federal Arrestee Drug Abuse Monitoring (ADAM) program and found that respondents' willingness to divulge their drug use varied based on the type of drug used and participants' geographic location and population group. 

For example, arrestees were far more willing to disclose marijuana use than use of other drugs: up to 93 percent of marijuana users self-disclosed their use, the study found, but self-disclosure of cocaine and crack use sometimes ran as low as 28 percent. 

The self-reported ADAM surveys were coupled with testing of urine samples from participants; given the disparities found in the new study, co-author Bruce Johnson said drug testing should accompany other drug studies in order to ensure accuracy. "Users of such surveys need to continually ask whether reported differences in drug use reflect actual differences in use or differences in willingness to disclose use," he said.

The research was reported in the Journal of Drug Issues (Vol. 35, No. 4).