The Schaefer Lab
Current Studies
Because many of the environmental exposures we study cannot be manipulated experimentally, our group relies heavily on data from longitudinal cohort studies, many of which have been following their participants for years--or even decades. We are especially interested in cohorts of twins, since twin research offers a unique avenue to dissect the intricate interplay between genetic predisposition and environmental factors, generating insights into the causal status of associations between different environmental factors and mental health.
The Vanderbilt University Twin Research Center (VUTRC)
Our lab is currently in the process of assembling a representative cohort of adolescent and young-adult twins in the state of Tennessee. These participants will power our lab's original data-collection efforts, including projects that combine twin methods with high-frequency data collection to better understand causal relationships between the brain, psychosocial stress, and substance use.
Using Longitudinal Twin Studies to Understand the Causal Effects of Substance use on the Brain
Our work uses data from multiple longitudinal twin studies across the United States to better understand the causal effects of long-term alcohol, cannabis, and nicotine use on brain health. This research has contributed to ongoing debates in the U.S. regarding the legalization of recreational cannabis use by demonstrating that adolescent cannabis use has little to no causal, long-term effects on mental health and cognitive ability, but that frequent use may contribute to reduced educational attainment through lowered academic performance.
Pathways Connecting Childhood Socioeconomic Disadvantage to Later-Life Substance Use
Socioeconomic disadvantage in early life has been shown to robustly predict greater risk of problematic substance use in adolescence and adulthood. However, the mechanisms by which this association operates remain poorly understood. Our work seeks to fill this gap by both identifying the environmental factors that connect disadvantage and later substance use, as well as understanding how early disadvantage might shape brain development in ways that predispose certain individuals to substance use and addiction.
Enduring Mental Health
Our work suggests that only a small fraction of the population (<15%) will manage to avoid developing a diagnosable mental health problem by midlife. We've labeled these individuals as experiencing "enduring mental health," and argued that studying their life circumstances can provide clues regarding the long-term maintenance of mental health in much the same way that studying centenarians can inform mechanisms of healthy aging.
