Substance Abuse Linked With Decreased Brain Volume In Women
A new study published in the journal Radiology shows stimulant drug abuse has long-term effects on brain volume in women, however, the effect was not found in men. Researchers found brain structures linked to reward, learning, and executive control showed significant changes, even after individuals had abstained from drug use for prolonged periods.
“We found that after an average of 13.5 months of abstinence, women who were previously dependent on stimulants had significantly less gray matter volume in several brain areas compared to healthy women,” said the study’s senior author, Jody Tanabe, M.D., professor of radiology, vice chair of Research, and Neuroradiology Section Chief at the University of Colorado Denver School of Medicine. “These brain areas are important for decision making, emotion, reward processing, and habit formation.”
In the study, the researchers hoped to identify how brains of people dependent on stimulants were different from the brains of individuals who had no history of drug abuse.
“We specifically wanted to determine how these brain effects differed by gender,” Dr. Tanabe said.
To do this, the researchers evaluated structural brain magnetic resonance imaging (MRI) exams from 127 men and women, including 59 individuals (28 women and 31 men) who were previously dependent on cocaine, amphetamines, and/or methamphetamine for an average of 15.7 years, and 68 healthy control participants (28 women and 40 men) who were matched for age and gender.
According to the results, the women who were previously dependent on stimulants showed significantly less gray matter volume in frontal, limbic, and temporal regions of the brain.
“While the women previously dependent on stimulants demonstrated widespread brain differences when compared to their healthy control counterparts, the men demonstrated no significant brain differences,” Dr. Tanabe said.
The researchers attempted to see how these brain volume differences were related to behaviors as well, concluding lower regional gray matter volumes were associated with behavioral tendencies to seek reward and novelty.
“Lower gray matter volumes in women who had been stimulant dependent were associated with more impulsivity, greater behavioral approach to reward, and also more severe drug use,” Dr. Tanabe said. “In contrast, all men and healthy women did not show such correlations.”
Dr. Tanabe and team say these findings may give an indication of the biological processes underlying the clinical course of stimulant abuse in men and women.
“Compared to men, women tend to begin cocaine or amphetamine use at an earlier age, show accelerated escalation of drug use, report more difficulty quitting and, upon seeking treatment, report using larger quantities of these drugs,” she said. “We hope that our findings will lead to further investigation into gender differences in substance dependence and, thus, more effective treatments.”