"Drug testing of any kind, including for cause or suspicion, was not a significant predictor of marijuana use. These results remained for all samples, even after controlling for student demographic characteristics."
Source
Yamaguchi R, Johnston LD, O'Malley PM. Relationship between student illicit drug use and school drug-testing policies. J Sch Health. 2003;73(4):159-164. doi:10.1111/j.1746-1561.2003.tb03596.x
