The more greatly attested habit creating methamphetamine is more serotonergic than the lesser reinforcing amphetamine. Most modern research suggests that 5-HT is "negatively" correlated with the addiction forming potential of psychostimulants, this is not saying that SRI properties cannot be considered beneficial. In fact, the above was proven by Rothman for releasing agents under the PAL-287 program of related molecules. What was somewhat interesting is that although the reason for the lack of reinforcement of RTI-112 is now well established, closely related RTI-111 was able to behave in ways that might be typical for a nonselective SNDRI such as cocaine. The role of the NET is not completely deleterious. In a recent paper by Rothman on transporter substrates, he establishes that for releasers that are amphetamine-like, discrimination stimulus is more accurately dictated by NE release than DA release. This argument does not mitigate a case against the importance of DA, but is suggestive that catecholamine "in general" is important. the exact ratio being 50:50 in the case of methylphenidate.