Decreased Serum Glutamate Levels in Male Adults with Internet Gaming Disorder: A Pilot Study

Objective: Alteration in glutamatergic neurotransmission and dopaminergic dysfunction has been implicated in both the initiation and expression of addiction related behaviors. This pilot study was aimed to investigate the serum levels of glutamate and dopamine in adults with internet gaming disorder (IGD). Methods: We measured serum levels of glutamate and dopamine in male participants with IGD (n=26) and age-matched healthy controls (n=25). Clinical interviews were performed to identify IGD and to rule out psychiatric comorbidities. Serum levels of glutamate and dopamine were examined by enzyme immunoassays using ELISA Kits. Results: Serum levels of glutamate were lower among IGD than control (IGD: 24.184±12.303 g/ml; control: 33.676±12.413 g/ml; t=2.742, p=0.008), while levels of dopamine did not differ between. Serum glutamate and dopamine levels did not correlate with gaming hours and exposure to game in the IGD group. But serum glutamate levels were positively correlated with the dopamine levels (r=0.360, p=0.013). Conclusion: Our results suggest that altered glutamatergic neurotransmission may contribute to the pathophysiology of IGD.