About the Project

Use of illicit stimulants, particularly methamphetamine, is at an alarmingly high level in certain populations of youth. Illicit stimulants are extremely habit-forming and hazardous, and use is linked to increases in HIV risk. Their use often portends an ominous future for youth who have progressed beyond gateway drugs to this hard-drug class. Yet, there is insufficient knowledge about the processes underlying the early development of this behavior and its likely risks. The proposed research focuses on several of the most promising processes consistently uncovered in multiple independent lines of basic research but not previously applied to adolescent stimulant use or HIV risk. Two sets of processes of focus are:

  1. Spontaneous or implicit cognitive processes, which encode and activate learned associations promoting risk behavior; and
  2. Protective, specific executive functions that inhibit or at least dampen the effects of such associations on behavior.

These processes have been well researched in neuroscience, basic research on memory, and decision theory, and they have been increasingly applied to other drugs of abuse in a host of studies during the past several years. The present project offers a novel line of inquiry that not only studies the main effects of these processes on teenage stimulant use and HIV risk, but tests a new synergistic (interaction) model derived from recent dual-process models that receive converging support from basic research and several studies on other addictive behaviors. In addition to the advance of predictive models of risk behavior, dual-process models can help explain more specific patterns, for example:

  1. Why do some youth progress from gateway illicit drugs (e.g., marijuana) to illicit stimulants, while others from the same at-risk population appear to be protected from this progression?
  2. What mediates habitual levels of risk behavior and strong predictive effects of previous drug habits?
  3. What processes supported by extensive basic research best predict growth in stimulant use and risky sexual tendencies?
  4. Which specific executive functions show the best protective effects on risk behaviors in at-risk adolescents?

To address these and other related questions, the project’s major study employs a three-wave, intensive longitudinal design using validated, primarily lab-based assessments across ages during which drug use progression to illicit stimulants and onset of hazardous sex are most likely in an at-risk teenage population. Despite this risk, the target population is quite amenable to mobile lab-based, computerized assessment and future intervention. The studied processes are relevant to future interventions, because they are sufficiently specific and have been delineated thoroughly in several independent lines of previous research. Thus, clear implications can emerge from the evaluation of the studied alternative models of risk behavior. The integration of validated lab-based methods and processes into an “indicated” population study of youth helps the project have potentially substantial implications for innovation in theories of drug use and HIV risk as well as future interventions that could target the studied processes.


Alan Stacy
Alan Stacy, PhD
Principal Investigator
Email address: alan.stacy@cgu.edu

Susan Ames
Susan L. Ames, PhD
Co-Principal Investigator
Email address: susan.ames@cgu.edu

Ongoing Activities

This research project is currently in the process of recruiting and assessing subjects. For more information, please contact Amy Custer at amy.custer@cgu.edu.


Data collection and analysis is currently ongoing. For more information, please contact Amy Custer at amy.custer@cgu.edu.


Funding for Teenage Stimulant Use: Neurally Plausible Spontaneous and Reflective Processes was provided by Award Number R01 DA024659 from the National Institute On Drug Abuse. The content displayed is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute On Drug Abuse or the National Institutes of Health.