On July 10, 1995, Jon Gettman and "High Times" Magazine filed another rescheduling petition with the DEA. This time, instead of focusing on cannabis' medical uses, the petitioners claimed that cannabis did not have the "high potential for abuse" required for Schedule I or Schedule II status. They based their claims on studies of the brain's cannabinoid receptor system conducted by the National Institute of Mental Health (NIMH) between 1988 and 1994. In particular, they claim that a 1992 study by M. Herkenham et al., "using a lesion-technique, established that there are no cannabinoid receptors in the dopamine-producing areas of the brain". Other studies, summarized in Gettman's 1997 report "Dopamine and the Dependence Liability of Marijuana", showed that cannabis has only an indirect effect on dopamine transmission. This suggested that cannabis' psychoactive effects are produced by a different mechanism than addictive drugs such as amphetamine, cocaine, ethanol, nicotine, and opiates. The National Institute on Drug Abuse, however, continued to publish literature denying this finding. For instance, NIDA claims the following in its youth publication "The Science Behind Drug Abuse":