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© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

Perturbations in dopamine system function may increase risk of substance use disorder (SUD). We recently demonstrated that neuromelanin (NM) MRI signal in the substantia nigra, a non-invasive index of dopamine system function, is elevated in long term cocaine users (Cassidy et al., 2020). However, it is unclear whether elevated NM-MRI signal is linked to risk of SUD, or is a byproduct of long-term drug use. Our prior work failed to show relations between NM-MRI signal and functional engagement of ventral striatum during a monetary reward task. However, social experiences are commonly linked to drug use and relapse. Given that, NM-MRI signal may be more closely linked to ventral striatal engagement during social, rather than monetary reward processing. Emerging adults (n = 33, 21.88 ± 4.35 years) with varying levels of substance abuse, but without SUD, underwent NM-MRI and fMRI during social and monetary reward processing tasks. Voxelwise analysis within the substantia nigra (SN) demonstrated lower NM-MRI signal was associated with more severe substance abuse. Lower right ventral striatal engagement to social reward was also associated with more severe substance abuse. This relation was moderated by SN NM-MRI signal such that diminished striatal response to reward was associated with greater substance abuse among those with low NM-MRI signal, but lower substance abuse among those with high NM-MRI signal. Unexpectedly, higher right ventral striatal engagement during monetary reward was associated with more severe substance abuse. This relation was moderated by SN NM-MRI signal such that greater striatal response to reward was associated with greater substance abuse among those with low NM-MRI signal. Taken together, we provide preliminary evidence that, in emerging adults, low rather than high dopamine system function may increase risk of substance abuse, and strengthen the association between substance use and the brain’s sensitivity to social and monetary outcomes in different ways.

Details

Title
Substance Abuse in Emerging Adults: The Role of Neuromelanin and Ventral Striatal Response to Social and Monetary Rewards
Author
Jarcho, Johanna M 1 ; Wyngaarden, James B 1 ; Johnston, Camille R 1   VIAFID ORCID Logo  ; Quarmley, Megan 1 ; Smith, David V 1   VIAFID ORCID Logo  ; Cassidy, Clifford M 2 

 Department of Psychology, Temple University, Philadelphia, PA 19122, USA; [email protected] (J.B.W.); [email protected] (C.R.J.); [email protected] (M.Q.); [email protected] (D.V.S.) 
 University of Ottawa Institute of Mental Health Research, Affiliated with The Royal, Ottawa, ON K1Z 8N3, Canada; [email protected] 
First page
352
Publication year
2022
Publication date
2022
Publisher
MDPI AG
e-ISSN
20763425
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2642344390
Copyright
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.