The relationship between duration of abstinence and gray-matter brain structure in chronic methamphetamine users

ABSTRACT

Background: Brain structural findings in chronic methamphetamine users have been inconsistent. Identifying contributing influences (e.g., sex, abstinence duration) can help clarify the clinical course of recovery.

Objectives: We studied the effects of long-term methamphetamine abstinence on gray-matter volume. Our hypothesis was that smaller volume early in abstinence would precede long-term recovery.

Methods: Individuals who used methamphetamine (≥100 g lifetime use, mandated to residential treatment for methamphetamine-positive urine; 40 men, 21 women), undergoing supervised abstinence (men: 12–400 days; women: 130–594 days), were compared to healthy controls (49 men, 36 women) using T1-weighted MRI. Volumes of orbitofrontal, anterior cingulate and parietal cortex, hippocampus, and striatum were measured using Freesurfer software. Associations of volumes with abstinence duration were tested in males and females separately because their abstinence times differed (121.5 ± 124.5 vs. 348.0 ± 128.6 days, p < 0.001); only males were studied in early abstinence. The General Linear Model was used to test effects of abstinence duration and group (methamphetamine users vs. controls).

Results: In males, duration of abstinence was multivariate significant for gray-matter volumes (p = 0.017). Abstinence duration was associated with increases in volumes of the orbitofrontal and parietal cortices (ps = 0.031, 0.016) and hippocampi (ps = 0.044). Irrespective of abstinence, male methamphetamine users had smaller hippocampi than male controls (p = 0.008). Females showed no significant effects of group or abstinence.

Conclusions: In males, abstinence from methamphetamine appears to result in volumetric increases in regions important for cognitive function, which may affect recovery during the course of treatment. Data from the period of early abstinence are required to evaluate volumetric changes in females.

KEYWORDS:

• Methamphetamine
• abstinence
• magnetic resonance imaging
• volumes of interest

Disclosure statement

The authors report no relevant financial conflicts.

Additional information

Funding

This research was supported by grants from the National Key Research and Development Program of China [No. 2017YFC1310401], the Science and Technology Department of Sichuan Province [Grant No. 2017HH0059]. Dr. London was supported by endowments from the Thomas P. and Katherine K. Pike Chair in Addiction Studies and the Marjorie M. Greene Trust. These grants did not have any role in the study design, analyses, interpretation of results, manuscript preparation, or approval to submit the final version of the manuscript for publication.