PRINCIPAL INVESTIGATOR: JANOWSKY, AARON J.
GRANT NUMBER: P50 DA018165-07S1
ABSTRACT: This project is a supplement to the Methamphetamine Abuse Research Center (MARC; P50 DA018165-06). It adds groups of subjects dependent on both methamphetamine (MA) and alcohol (EtOH) as well as nicotine. The overarching aim of this supplement is to extend the program to develop intermediate phenotypes of impulsive choice to multiple addiction groups.
Specific Aims 1 and 2 will identify differences in brain function and anatomy of impulsive choice among active MA users, newly abstinent MA-dependent individuals, and newly abstinent MA & EtOH subjects. Description of more specific neural bases of decision making can provide improved targets for pharmacological and behavioral treatments for addiction.
Specific Aim 3 proposes to link immune response with intermediate imaging phenotypes of impulsive choice in human polysubstance dependent patients.
METHODS: Two new groups of 20 subjects in early remission (2 weeks to 3 months) will be recruited. One group will be dependent on MA, EtOH and nicotine, the other only on MA and EtOH. Groups proposed in the original MARC Components 5, 7 and 8 will be reconfigured to include these extra groups and ensure that one control group consists of never-smokers. Subjects will be evaluated with functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI) and voxel based morphometry (VBM) in order to identify the anatomical and functional networks that underlie impulsive choice. Measures of immune dysregulation (from Components 5 and 8) will be investigated as factors responsible for disruption of decision networks in humans and in animals performing impulsivity tasks.