Inclusion Criteria:  Age 13-17 years English as primary language (both child and legal guardian) DSM-5 criteria for Autism Spectrum Disorder IQ >70 per Weschler Abbreviated Scale of Intelligence (WASI) Informed assent for the study (The guardian must also give written informed consent) For sexually active females, agreement to use two forms of contraception during trial to avoid pregnancy  Exclusion Criteria:  Any neurological disorder (e.g., cerebral palsy, fetal alcohol syndrome, cerebral neoplasm, bacterial meningitis, epilepsy, etc.) Genetic disorders (e.g., Fragile X, Rett Syndrome, etc.) Contraindications for MRI, such as metallic or electronic implants in the body, or severe claustrophobia Unstable psychiatric disorder expected to require psychotropic medication changes over the course of the study History of psychotic disorder Any condition that would prevent the subject from being able to complete study protocol Unstable medical illness such as diabetes, asthma, thyroid disease Currently on medications that cause respiratory depression, e.g. opioids, benzodiazepines Clinically significant suicidal ideation as assessed by the Columbia Suicide Severity Rating Scale History of intolerance to gabapentin or pregabalin Current substance use (including nicotine) Current treatment with gabapentin History of renal dysfunction Subjects who weigh more than 88 kg Pregnancy in female participants.