Analyzing 14 years of data from about 247,000 middle and high school students, Yvonne Terry-McElrath, Patrick O’Malley, and Lloyd Johnston find that students subject to random school drug testing tended to use less marijuana and more of other illicit drugs. While marijuana use may be detectable in a urinalysis for weeks or even months, most other illicit drugs are undetectable within about a day. The researchers speculate that students subject to drug screens may switch from cannabis to other drugs with significantly shorter detection times. A report of this research is available in the [*Journal of Adolescent Health*](http://dx.doi.org/10.1016/j.jadohealth.2012.11.020).

More about Terry-McElrath, O’Malley and Johnston find association between school drug testing and increased use of illicit drugs other than marijuana >