Results: Our analysis of the primary outcome identified 30 subjects as responders, who either reduced
methamphetamine use consistently over time or achieved abstinence. Moreover, topiramate recipients
had a significantly steeper slope in methamphetamine reduction and accelerated to abstinence faster than
placebo recipients. For the secondary outcomes in weeks 6–12, we identified 40 subjects as responders
(who had significant reductions in methamphetamine use) and 65 as non-responders; topiramate recipients
were more than twice as likely as placebo recipients to be responders (odds ratio = 2.67; p = 0.019).
Separate analyses of the outcomes during weeks 1–12 yielded similar results.