Publications by Year: 2022

Aims

This study was designed to assess links between lifetime levels of marijuana use and accelerated epigenetic aging.

Design

Prospective longitudinal study, following participants annually from age 13 to age 30.

Setting and participants

A community sample of 154 participants recruited from a small city in the Southeastern United States.

Measurements

Participants completed annual assessments of marijuana use from age 13 to age 29 and provided blood samples that yielded two indices of epigenetic aging (DNAmGrimAge and DunedinPoAm) at age 30. Additional covariates examined included history of cigarette smoking, anxiety and depressive symptoms, childhood illness, gender, adolescent-era family income, and racial/ethnic minority status.

Findings

Lifetime marijuana use predicted accelerated epigenetic aging, with effects remaining even after covarying cell counts, demographic factors and chronological age (β’s = 0.32 & 0.27, p’s < 0.001, 95% CI’s = 0.21–0.43 & 0.16–0.39 for DNAmGrimAge and DunedinPoAm, respectively). Predictions remained after accounting for cigarette smoking (β’s = 0.25 & 0.21, respectively, p’s < 0.001, 95% CI’s = 0.14–0.37 & 0.09–0.32 for DNAmGrimAge and DunedinPoAm, respectively). A dose-response effect was observed and there was also evidence that effects were dependent upon recency of use. Effects of marijuana use appeared to be fully mediated by hypomethylation of a site linked to effects of hydrocarbon inhalation (cg05575921).

Conclusions

Marijuana use predicted epigenetic changes linked to accelerated aging, with evidence suggesting that effects may be primarily due to hydrocarbon inhalation among marijuana smokers. Further research is warranted to explore mechanisms underlying this linkage.

This study examined an intervention designed to improve sense of belongingness for new
students at a medium-sized, four-year, public university in the Eastern United States. A
randomized controlled trial was used to assess the impact of The Connection Project, a novel, 9-
session intervention in a sample of 128 first-year students (77 treatment, 48 waitlist control).
Given the onset of COVID-19, students received a hybrid in-person/online intervention. At post-
intervention, the intervention group reported a significantly higher sense of school
belongingness, after accounting for baseline levels, than control group students. Post-hoc
analyses of moderation by demographic variables indicate that the intervention functioned
similarly for students from a variety of backgrounds in this sample. These results are interpreted
as suggesting the potential value of this intervention to promote a sense of community and
connection among new students in college, whether delivered in-person or online.