Multimodal MRI Reveals Brain Structural Differences and Executive Dysfunction in Early Methamphetamine Abstinence

BackgroundMethamphetamine use disorder (MUD) is known to have profound effects on brain structure and cognitive functions. Understanding the extent of these neurobiological changes during the early abstinence period is crucial for developing targeted rehabilitation strategies. ObjectiveThis study aimed to investigate structural brain alterations, and cognitive functions, in early abstinent methamphetamine users compared with healthy controls. MethodsA total of 27 participants were included, comprising 13 participants with MUD in early abstinence (<30 days - mean age: 37.4 {+/-} 9 years, 66% female) and 14 age- and sex-matched healthy controls (mean age: 39.2 {+/-} 11.1 years, 74% female). All subjects underwent brain MRI scans using a 3T scanner, acquiring T1-weighted and myelin-sensitive imaging data. They also completed the Tower of London (TOL) cognitive assessment to evaluate executive functioning. Grey matter volumetric analysis was performed using T1-weighted images, and both regional and global myelin measures were quantified for group comparison. ResultsBehaviourally, MUD participants demonstrated significantly longer execution times for correct solutions (p=0.01), required more attempts to solve problems (p=0.02), and achieved fewer correct solutions on the first attempt (p=0.01). Neuroimaging analyses revealed significant cortical thinning in the left lateral occipital and right lingual cortices among MUD participants. Additionally, cortical volumes of the right superior frontal and lingual cortex were significantly reduced in the MUD group. Vertex-wise analysis further showed a negative correlation between duration of methamphetamine use and the volume of multiple cortical regions. ConclusionsThese findings indicate that methamphetamine use is linked to poorer executive function, and cortical changes, while the absence of group differences in myelin measures suggests that grey-matter is more vulnerable to meth-induced damage than white-matter.