The size of a woman鈥檚 grey matter could depend on her dependence (Image: Piotr Powietrzynski/Getty)
Don鈥檛 do drugs, kids. Especially if you鈥檙e female. Women dependent on stimulants like cocaine and methamphetamine appear to have less grey matter, even after they stop using them. Weirdly, men鈥檚 brains don鈥檛 show this difference.
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The brain regions most affected are those involved in reward, emotion and learning 鈥� although it isn鈥檛 clear yet whether the smaller than average size of these brain areas could be a cause or effect of addiction. , at the University of Colorado Hospital in Aurora, hopes these results will help lead to a better understanding of sex differences in substance abuse, and better, more distinct treatments for women.
Tanabe鈥檚 team used MRI scans to measure the brain volumes of 59 people previously dependent on stimulants and compared them with people who have never been dependent on these kinds of drugs. On average, the 28 women who had formerly been dependent on a stimulant drug had a smaller volume of grey matter in their prefrontal cortices, temporal lobes, insulae and other regions. This effect was not seen in men.
Shrinking brains
The women who had been addicted also differed in their personalities 鈥� on average, they were more impulsive and more reward-driven. We already know that women respond differently to stimulants: they start taking the drugs earlier, and may have more difficulty quitting. It鈥檚 possible that this pattern of female addiction could be linked to the brain size difference.
However, it鈥檚 unclear whether less grey matter causes female addictive behaviours, or if addiction might shrink these brain regions. 鈥淭he question of causality is complex. There is evidence for both pre-existing and post-drug changes in brain structure and function,鈥� says Tanabe.
from King鈥檚 College London says longitudinal studies, which follow the same people over time, are necessary to untangle the causes and effects before any treatment decisions could be based on this research.
Currently, men and women receive the same treatment for stimulant dependence. from Yale University suggests that the female brain may be more vulnerable to toxic effects of drugs and this study 鈥渨ould suggest extended treatment is necessary 鈥� perhaps more so for women鈥�.
Journal reference: Radiology, DOI:
