Pilot Study of the Effect of Ibudilast on Neuroinflammation in Methamphetamine Users

Inclusion Criteria: * abstinent from all drugs except marijuana and methamphetamine and have a negative urine drug screen on test days * Meet diagnosis for recent Methamphetamine-Use Disorder (DSM-V) or does not meet any substance-use disorders Exclusion Criteria: * Known sensitivity to ibudilast * Left handed * MRI contraindications * Clinically significant neurological, endocrine, renal, hepatic, or systemic diseases that would compromise safe participation or confound outcomes * Any psychiatric diagnoses or primary psychotic or mood disorders (past depression diagnoses allowed) * Any drug use disorder diagnosis besides methamphetamine or tobacco * Any recreational or prescriptive use of psychotropic medications * Claustrophobia * Women who are pregnant or breast-feeding * Neurodegenerative diseases that present with neuroinflammation * More than 4 weeks abstinent from methamphetamine * rs6971 genotype that confers low translocator protein (TSPO) binding affinity to prevent unnecessary radiation exposure * Liver disease requiring medication or medical treatment and/or aspartate or alanine aminotransferase levels greater than 3 times the upper limit * Participation in any drug study in the last 3 months