AUTHOR=Raposo Pereira Filipa , McMaster Minni T. B. , Schellekens Arnt , Polderman Nikki , de Vries Yvon D. A. T. , van den Brink Wim , van Wingen Guido A. 

TITLE=Effects of Recreational GHB Use and Multiple GHB-Induced Comas on Brain Structure and Impulsivity

JOURNAL=Frontiers in Psychiatry

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2020.00166

DOI=10.3389/fpsyt.2020.00166

ISSN=1664-0640

ABSTRACT=Background and Aims:
Regular use of gamma-hydroxybutyrate acid (GHB) can induce GHB-induced comas. Other substance use disorders are associated with alterations in brain structure and impulsivity. Here, we aim to investigate if these are also modulated by either regular GHB-use or GHB-induced comas. 
Methods:
In a sample of human males, structural and diffusion neuroimaging data were collected for 27 GHB users with ≥4 GHB-induced comas (GHB-Coma), 27 GHB users without GHB-induced comas (GHB-NoComa), and 27 polydrug users who never used GHB (No-GHB). Structural brain parameters were analyzed macroscopically using voxel-based morphometry (VBM), and microscopically using tract-based spatial statistics (TBSS) and tractography. Impulsivity was assessed with the Barrat Impulsivity Scale (BIS).
Results:
In comparison to the other two groups, the GHB-Coma group showed higher fractional anisotropy in the body of the corpus callosum and lower mean diffusivity in the forceps minor (i.e. whole-brain TBSS analysis). No macrostructural differences, nor microstructural differences as assessed with tractography, were observed. The GHB-Coma group also reported higher impulsivity, which was more strongly associated with white matter volume and fractional anisotropy in tracts involved in impulse control (post-hoc analysis). GHB-use per se was neither associated with differences in brain structure nor with impulsivity. 
Conclusions:
The results suggest that multiple GHB-induced comas, but not GHB-use per se, are associated with microstructural alterations in white matter and with higher self-reported impulsivity, which in turn was associated with white matter tracts involved in impulse control.