The education programs can reduce drug use, provided that they use interactive methods that factor the development of interpersonal skills Most such programs are aimed at several substances usually cannabis. They may aim to increase knowledge about drugs, to reduce drug use or misuse, to delay onset of first use or to reduce the harm caused by drug use and reduce the number of news cases of problematic drug use. Mass media compaigns are apparently unable to reduce cannabis use, but they probably do increase the effect of programs and interventions. Although no medications are currently available for treating marijuana abuse, recent discoveries about the workings of the THC receptors have raised the possibility of eventually developing a medication that will block the intoxicating effects of THC. Such a medication might be used to prevent relapse of marijuana abuse by lessening or eliminating its toxicity.