Internet addiction (IA) is one of the common types of non-chemical addictions. The search for reliable predictors of IA development is the most important task of preventive medicine on the basis of a personalized approach to IA prevention. The article presents the results of a pilot stage of a multicenter national study in the search for genetic risk markers of IA development. Individuals from a cohort of young adults (mean [±SD] age, 22.96 ±1.9 years), 26.2% female) with IA (≥65 on the Chen Internet Addiction Scale, Chinese Internet Addiction Scale (CIAS), n = 44) and healthy individuals (<65, n = 20) were compared. A genetic panel (31 polymorphic loci in 22 genes), formed on the basis of a pathogenetic approach was used: polymorphic variants of genes that control neurotransmitter systems (dopamine (DA), serotonin, GABA-glutamate), endogenous opioid system and neurotrophin system. According to the results of the analysis using regression models, preliminary genetic markers of IA with non-zero predictive power (AUC 0.662) were detected for the first time: functional polymorphism rs6265 of the brain-derived neutrophic factor (BDNF) gene increases the likelihood of developing IA by 2.7 times (p = 0.018); exon 3 VNTR 48-bp polymorphism of the dopamine D4receptor gene (DRD4), in contrast, reduces the likelihood of IA development by 67.5% (p = 0.032). A protective effect (p = 0.039) of the rs2229910 polymorphism of the neurotrophic tyrosine kinase receptor type 3 (NTRK3) gene was also confirmed. A number of modulating risk markers and an intergenic interaction effect were revealed (between the genes of the dopamine D2 receptor and mu opioid receptor). All the genetic risk markers-modulators of ID are associated with DAergic mediation, thus confirming active involvement of the brain reward system in the etiology and pathogenesis of ID. This study is preliminary, but the fact of identifying significant genetic risk markers for the development of ID with a significant pathogenetic significance supports the correctness of the chosen research strategy and requires continuing studies on larger samples.