# Pallidum Functional Hypoconnectivity and Inhibitory Control as Partial Mediators of Environmental Influences on Tobacco and Marijuana Initiation

## TL;DR

Low socioeconomic status increases tobacco and marijuana use in teens partly due to environmental pollution and brain connectivity changes affecting impulse control.

## Contribution

Identifies a novel pathway linking low SES to substance use via PM2.5 exposure, pallidum-VAN connectivity, and inhibitory control.

## Key findings

- Low SES correlates with higher PM2.5 exposure and altered pallidum-VAN functional connectivity.
- Reduced inhibitory control partially mediates the link between low SES and substance use initiation.
- Environmental and neurocognitive factors together influence adolescent substance use behaviors.

## Abstract

Low socioeconomic status (SES) has been linked to higher rates of
tobacco and marijuana use initiation; however, the contributions of
environmental and neurocognitive factors remain underexplored. This study
investigates a potential pathway connecting low SES, fine particulate matter
(PM2.5) exposure, brain functional connectivity, and inhibitory control to
increased tobacco and marijuana use initiation among adolescents.

To examine the mediating roles of PM2.5 exposure, resting-state
functional connectivity between the right pallidum and the ventral attention
network (P-VAN rsFC), and inhibitory control in the relationship between low
SES and tobacco and marijuana use initiation.

Data were drawn from the Adolescent Brain Cognitive Development
(ABCD) study to assess associations between baseline SES, baseline PM2.5
exposure (based on zip code), baseline P-VAN rsFC, baseline inhibitory
control, and subsequent tobacco and marijuana use initiation. Mediation
models were used to determine whether PM2.5 exposure and changes in P-VAN
rsFC act as pathways linking low SES to diminished inhibitory control and
subsequent substance use initiation.

Low SES was associated with higher PM2.5 exposure, which, in turn,
was linked to alterations in P-VAN rsFC. These alterations were correlated
with lower inhibitory control, which significantly predicted tobacco and
marijuana use initiation over time. Inhibitory control partially mediated
the relationship between low SES and substance use initiation, indicating a
complex pathway influenced by environmental and neurocognitive factors.

This study identifies a potential mechanism linking low SES to
tobacco and marijuana use initiation through environmental and
neurobiological pathways. Understanding how PM2.5 exposure and
neurofunctional connectivity impact inhibitory control can provide valuable
insights for developing targeted interventions to reduce substance use among
adolescents in low SES environments.