Studies using animal modelssuggested that liver dysfunction could reduce METH clearance, increase brain drugconcentrations, and therefore enhance its psychotropic effects on locomotor activityin a dose-dependent manner (34).Hyperthermia-dependent liver damage has been observed in mice after acuteadministration of METH, accompanied by increased plasma aspartate, ALT, and plasmaammonia concentrations (12). The gene discussed is GPT; the disease is Decreased liver function.