Neural bases of methamphetamine-induced psychosis
Volume reductions in frontopolar and left perisylvian cortices
Administration of methamphetamine (METH) can cause schizophrenia-like symptoms, including hallucinations and delusions. This process is termed METH associated psychosis (MAP). In addition to similarity in clinical symptoms, as patients with MAP similarly respond to dopamine-antagonists, MAP is thought to be a human pharmaceutical model of schizophrenia. In the current study, Dr. Hidenori Yamasue from Department of Neuropsychiatry, Graduate school of Medicine, University of Tokyo and his co-researchers showed that, compared with demographically matched healthy controls, patients with MAP have smaller gray matter volume (GMV) in the periSylvian structures, such as inferior frontal and superior temporal gyri. Volume reductions in these structures have been repeatedly reported in patients with schizophrenia and supposed to be neural bases of psychotic symptoms. The current study also demonstrated smaller GMV in the frontopolar cortex (FPC), which is responsible for reward based decision making and moral judgment. The patients with MAP also have smaller volume in the orbitofrontal area which is considered to be the neural basis of reward based decision making. Further, GMV reduction in the FPC is correlated to severity of psychotic symptoms. This is the first computational analysis of brain morphology involving patients with MAP. These findings suggest that these brain regions play an important role in development of MAP. This study was conducted by Tokyo Metropolitan Matsuzawa Hospital, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, and the University of Tokyo’s Graduate School of Medicine. Part of this study was supported by the project of the Strategic Research Program for Brain Sciences sponsored by MEXT.
Yuta Aoki, Lina Orikabe, Yoichiro Takayanagi, Noriaki Yahata, Yuriko Mozue, Yasuhiko Sudo, Tatsuji Ishii, Masanari Itokawa, Michio Suzuki, Masataka Kurachi, Yuji Okazaki, Kiyoto Kasai, Hidenori Yamasue,
“Volume reductions in frontopolar and left perisylvian cortices in methamphetamine induced psychosis”,
Schizophrenia Research 2013/5/20, doi: 10.1016/j.schres.2013.04.029.