MA abusing participants will undergo a 1-day outpatient screening and if it is safe for the participants to proceed with the study they will participate in two inpatient phases of the study that will occur in the UCLA research setting, the General Clinical Research Center. The first inpatient stay will be 15 days, and the second will be a 9 days stay that includes drug administration and assessments. There will be at least a two week interval between inpatient phases. During the inpatient phases participants will receive alternating study drugs; atomoxetine or placebo and four sessions of IV MA administration or placebo.