PET imaging reveals brain functional changes in internet gaming disorder.

Abstract

Internet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D2 (D2)/Serotonin 2A (5-HT2A) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D2 receptor and glucose metabolism. Twelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and (11)C-N-methylspiperone ((11)C-NMSP) to assess the availability of D2/5-HT2A receptors and with (18)F-fluoro-D-glucose ((18)F-FDG) to assess regional brain glucose metabolism, a marker of brain function. (11)C-NMSP and (18)F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states. In internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D2 receptors was observed in the striatum, and was correlated to years of overuse. A low level of D2 receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex. For the first time, we report the evidence that D2 receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D2/5-HT2A receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects.