Prefrontal grey-matter changes in short-term and long-term abstinent methamphetamine abusers

Area of Science:

• Neuroscience
• Neuroimaging
• Addiction Research

Background:

• Chronic methamphetamine abuse is associated with cognitive deficits.
• Structural brain changes, particularly in grey-matter density, are suspected in methamphetamine users.

Purpose of the Study:

• To investigate grey-matter density differences between methamphetamine abusers and healthy controls.
• To examine the relationship between grey-matter density, cognitive performance, and abstinence duration in methamphetamine abusers.

Main Methods:

• Voxel-based morphometry was used to compare grey-matter density between 29 methamphetamine abusers and 20 healthy subjects.
• Cognitive function was assessed using the Wisconsin Card Sorting Test (WCST).
• Abstinence duration was categorized into short-term (<6 months) and long-term (>=6 months).

Main Results:

• Methamphetamine abusers exhibited reduced grey-matter density in the right middle frontal cortex compared to controls.
• Abusers made more errors on the WCST, indicating impaired executive function.
• Reduced grey-matter density in the right middle frontal cortex correlated with increased WCST errors.
• Long-term abstinent abusers showed less grey-matter density reduction and fewer WCST errors than short-term abusers, but more than controls.

Conclusions:

• Methamphetamine abuse is associated with prefrontal grey-matter deficits.
• These deficits may be partially reversible with extended abstinence.
• Cognitive impairments, specifically in executive function, are linked to these structural brain changes.