This study will link findings from neuroscience with clinical outcomes using contingency management (CM) to identify changes in brain structure and function that emerge during purely behavioral therapy for methamphetamine (MA) use.

This study will correlate MA-abstinence outcomes from an 8-week program of voucher-based incentives using an escalating schedule for 30 treatment-seeking, MA-dependent individuals with scores on tasks of working memory and assessments of neuropsychological and demographic status. At the beginning and end of the CM program, participants will participate in MRI scans while performing a working memory task and will complete a battery of select neurocognitive and psychological assays to address two specific aims: (1) to determine whether changes in neural function within frontostriatal circuitry from baseline to end of the 8-week CM program are associated with parallel changes in measures of cognitive control and impulsivity and with MA abstinence outcomes and (2) to determine whether structural changes in frontostriatal circuitry over the 8-week CM intervention correspond with neurocognitive, psychological and MA abstinence measures.

Inclusion Criteria:

• provide voluntary informed consent
• meet DSM-5 criteria for MA or amphetamine use disorder
• provide at least one urine sample positive for MA/amphetamine metabolites during screening (i.e. prior to the commencement of the study).
• aged 18-45
• right-handed
• English-speaking

Exclusion Criteria:

• currently receiving treatment for stimulant addiction or needing more intensive treatment than outpatient care
• meet DSM-5 criteria for substance use disorder other than nicotine
• unable to attend 4+ visits during the 2-week screening period or to complete measures
• Physical or mental illness that would require intervention that would alter imaging or that would interfere with safe study participation
• pregnant, claustrophobic, or have metal prostheses, cardiac pacemakers, or metal clips that are incompatible with the scanner
• HIV positive status
• unable to comprehend written or spoken English
• currently taking psychiatric medication

Data will be shared with other investigators following publication of the main paper or 2 years after the last subject completes participation, whichever comes first. Shared data will be stripped of all PHI and potentially personally identifying variables.

Requests should briefly state the concept of interest, provide a brief timeline for analyzing the data and preparing a manuscript, and include a copy of the CV of the investigator making the request and documentation of proof of training in the ethical treatment of human subjects in research.

The concept proposal will be evaluated based on three criteria, including the potential impact or contribution to the research in advancing knowledge; the feasibility of the proposed research; and that the aim of the proposed research will not overlap with any of the aims or planned analyses.