6/11/2026
A University of Pittsburgh study tracked adolescent brain chemistry for up to nine years — and found that lower dopamine early in adolescence, not higher, predicts greater substance experimentation.
PITTSBURGH — Teens who try alcohol, cannabis or nicotine may be responding to lower baseline dopamine — the brain's chemical messenger for motivation and reward — rather than an excess of it, according to a University of Pittsburgh School of Medicine study published June 11, 2026, in Nature Communications. The finding challenges a long-held assumption in the field.
Researchers followed more than 800 adolescents using the National Consortium on Alcohol and Neurodevelopment in Adolescence and Young Adulthood (NCANDA-A), a multi-site study that tracked brain development and substance use from early adolescence into adulthood. Critically, dopamine measurements were captured before substance use patterns were established — giving scientists a rare look at biology that may precede behavior, rather than simply reflect it.
"Our results suggest that, for some teens, risk-taking may act as a way to 'get the system going' when dopamine-related reward biology is lower at the start of adolescence," said Ashley Parr, Ph.D., lead and corresponding author of the study and research assistant professor of psychiatry at Pitt. "This finding is a big shift for the field because many people would assume higher dopamine activity would be linked to more substance use."
A Tool for Imaging the Dopamine System in Youth
Central to the research is a non-invasive MRI technique that measures iron in brain tissue as a marker for dopamine metabolism — closely related to the function of dopamine in reward-processing regions. Historically, dopamine processes have been hard to study in youth due to restrictions on the use of Positron Emission Tomography (PET) that require injecting a radionuclide tracer. To overcome theses limitations, iron neuroimaging was adopted for use in youth in the laboratory of Beatriz Luna, Ph.D., professor of psychiatry at Pitt, by then-postdoctoral fellow Bart Larsen, Ph.D., who subsequently joined the faculty at the University of Minnesota. Unlike most research on substance use that has been conducted after years of substance use exposure, this approach let researchers measure dopamine-related biology in adolescents, before any use had begun, and scan them repeatedly throughout the course of adolescence when substance use experimentation takes place.
The team analyzed more than 6,000 repeated assessments of self-reported substance use, impulsivity and behavioral control, alongside brain scans collected annually for up to nine years.
A Distinct Pattern — and What It Means
Not all participants followed the same path. Some showed minimal substance use throughout the entire study period. Others fit a "youth peak" pattern: experimentation rose in early adolescence, then declined by the mid-twenties. Teens in that group had significantly lower dopamine levels than all other groups — including those whose use continued into adulthood.
As "youth peak" participants aged, their dopamine levels increased steadily. That rise coincided with declining substance use and with the ongoing maturation of prefrontal cortex-mediated cognitive control — the brain region and process governing impulse control and long-term decision-making, which continues developing into the mid-twenties.
Teens in this group showed what researchers describe as relatively low dopamine-related biology early in adolescence — lower baseline activity in the brain's reward circuits — which appeared to drive compensatory reward-seeking behavior. Most did not develop substance use disorder as adults.
"The key question isn't who experiments, but who continues, and who escalates their use into adulthood," Parr said. "By tracking teens over time, we were able to pinpoint early brain and behavioral markers that help distinguish temporary, developmentally typical experimentation from patterns that may signal greater long-term risk."
What This Could Mean for Teens
Non-invasive dopamine measurement — requiring only a standard MRI scan — may eventually give researchers and clinicians a tool to identify adolescents whose brain chemistry suggests elevated risk during a critical window of development, when early guidance could have the greatest impact. The findings also open a research window into other forms of reward-seeking: the same dopamine-driven sensitivity that draws teens toward substances may also drive engagement with related forms of risk-taking and highly reinforcing social media environments.
"Risk-taking is a normal part of being a teenager, and for most kids it's a phase that peaks and then eases," said Luna, senior author of the study. "Parents can help by steering that drive for new, rewarding experiences toward positive social outlets like team sports, so teens can chase that 'reward' in healthier places."
Frequently Asked Questions
Q: Why do teens often stop experimenting with substances by their mid-twenties?
A: University of Pittsburgh researchers found that as dopamine levels in the brain's reward system increased during late adolescence and early adulthood, substance use declined among teens who had experimented earlier. That maturation coincides with continued development of the prefrontal cortex, the brain region that governs planning and impulse control.
Q: How did researchers measure dopamine in adolescents without invasive testing?
A: Scientists used an MRI technique that measures iron in brain tissue as a proxy for dopamine content. The approach requires no radioactive tracers and can be applied using standard MRI equipment.
Q: Does teen substance experimentation usually lead to addiction?
A: Not always. The study found that most participants whose substance use peaked during adolescence showed significant declines by their mid-twenties and did not develop substance use disorder as adults.
Additional Resources
- Published study: Developmental variation in basal ganglia tissue iron, neurocognitive functioning, and impulsivity is associated with substance use trajectories in youth, Nature Communications
- EurekAlert! release: Lower dopamine may drive teen risk-taking that fades with age
- Researchers Map Cognitive Development Through Adolescence
- Scientists Get Clearer Picture of Developing Teen Brain
- Adolescent Brain Development and Establishing Adult Trajectories
Authors and Funding
Authors: Pitt co-authors of this research are Daniel Petrie, Ph.D., Finnegan Calabro, Ph.D., Will Foran, Ph.D., Douglas Fitzgerald, Ph.D., and Duncan Clark, M.D., Ph.D. Additional co-authors are from Carnegie Mellon University, University of Minnesota, University of California San Diego, University of North Carolina Wilmington, University of Tulsa and Duke University.
Funding and Disclosures: This research was supported by the National Institutes of Health (grant 5R01MH080243-07), the Developmental Alcohol Research Training Program from the National Institute on Alcohol Abuse and Alcoholism (grant T32 AA007453), the National Institute on Drug Abuse (grant K23DA057486), the Brain and Behavior Research Foundation, the Jacobs Foundation and the Staunton Farm Foundation.
