Studies Overview

The “SoCal Cohorts” (SCC) examine youth and young adult attitudes and behaviors related to vaping, drug, and alcohol use and explore how mental stressors, social media, and life events impact health. The SCC longitudinal studies have been ongoing since 2013, and findings have provided valuable evidence for policymakers and stakeholders.

SCC involves a large cohort of students from over 25 high schools representing diverse socioeconomic backgrounds and geographical locations. A sample of over 9,000 students from different age groups and grade levels has been followed through multiple waves of data collection, some through young adulthood. We have completed over 25 waves of data collection so far, with each wave spanning approximately 6 months. The multi-year approach allows researchers to observe trends, changes, and developmental trajectories over an extended period of time, offering nuanced and reliable insights into the behaviors that impact adolescent and young adult health.

SoCal Cohorts Population Data Sources

The USC EPIC Study is a 4-year, longitudinal research study. The study provides timely information on the causes and consequences of modern health issues facing teens. EPIC surveys the Class of 2027 throughout high school and collects data on teen’s attitudes and behaviors related to nicotine, cannabis, and other drug use as well as explores how mental stressors, social media, and life events impact health.

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The ADVANCE Study is a 5-year, longitudinal behavioral research study from 2020-2025. The ADVANCE study has a total of 11 waves of data collection, with 4,400 participating students.
The study surveys youth from 11 schools across the Southern California region and provides current information on the biggest health issues facing teens.

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The Happiness and Health (H&H) Study began in 2013-2014. H&H has a total of 14 waves of data collection, with over 3,300 young people participating in the study.
Since its inception, H&H has generated detailed prospective data on key e-cigarette product exposures and use patterns, use of other tobacco products, and mental health.

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Implications for Prevention

The USC SoCal Cohorts (SCC) collectively includes over 9,000 teens and young adults in Southern California with data collection spanning from 2013 to 2027. The studies provide timely evidence on the attitudes, behaviors, and social-environmental factors impacting mental health and substance use among youth and young adults. These cohort studies provide an evidence-base for policymakers, educators, and community stakeholders to take action towards addressing the complex health issues facing young people today through prevention programs and policy change.

Other Research Studies

The Tobacco & Cannabis Retail Environment and Adolescent Vaping

This ongoing study uses data from the ADVANCE cohort, tobacco retailer and cannabis dispensary license lists, and the American Community Survey integrated with geospatial methods to investigate the impact of tobacco and cannabis retail density and neighborhood disadvantage on adolescent nicotine and cannabis vaping. As part of this study, we will also be collecting new data through store observations of tobacco and cannabis retailers around Southern California to determine whether specific features of the retail environment (e.g., marketing, product types, ID compliance) influence youth nicotine and cannabis use.

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Simulating Point-of-Sale Cannabis Price Discounts to Examine Young Adult Purchasing Behavior and Attitudes

This ongoing experimental study, supported through an internal institutional funding mechanism for early career investigators, examines how retail cannabis price promotions (e.g., percentage-off discounts) influence young adult purchasing behavior, product selection, and perceived affordability in a highly realistic simulated dispensary environment. Findings will inform regulatory strategies aimed at mitigating problematic cannabis use among young adults.

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