Higher striatal glutamate in male youth with internet gaming disorder.

Internet gaming disorder (IGD) was included in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as a research diagnosis, but little is known about its pathophysiology. Alterations in frontostriatal circuits appear to play a critical role in the development of addiction. Glutamate is considered an essential excitatory neurotransmitter in addictive disorders. This study's aim was to investigate striatal glutamate in youth with IGD compared to healthy controls (HC). Using a cross-sectional design, 25 adolescent male subjects fulfilling DSM-5 criteria for IGD and 26 HC, matched in age, education, handedness and smoking, were included in the analysis. A structural MPRAGE T1 sequence followed by a single-voxel magnetic resonance spectroscopy MEGA-PRESS sequence (TR = 1500 ms, TE = 68 ms, 208 averages) with a voxel size of 20 mm3 were recorded on 3 T Siemens Magnetom Prisma scanner. The voxel was placed in the left striatum. Group comparison of the relative glutamate and glutamine (Glx) was calculated using regression analysis. IGD subjects met an average of 6.5 of 9 DSM-5 IGD criteria and reported an average of 29 h of weekly gaming. Regression analysis showed a significant group effect for Glx, with higher Glx levels in IGD as compared to HC (coef. = .086, t (50) = 2.17, p = .035). Our study is the first to show higher levels of Glx in the striatum in youth with IGD. The elevation of Glx in the striatum may indicate hyperactivation of the reward system in IGD. Thus, results confirm that neurochemical alterations can be identified in early stages of behavioral addictions.

Excessive and pathological Internet use - Risk-behavior or psychopathology?

Pathological Internet use (but only with respect to gaming) is classified as mental disorder in the ICD-11. However, there is a large group of adolescents showing excessive Internet use, which may rather be considered adolescent risk-behavior. The aim was to test whether pathological and excessive Internet use should be considered as "psychopathology" or "risk-behavior". A representative, cross-sectional sample of 11.110 students from 10 European Union countries was analyzed. Structural equation models, including the factors "risk-behavior" and "psychopathology" and the variables excessive and pathological Internet use, were tested against each other. "Risk-behavior" was operationalized by several risk-behaviors (e.g. drug abuse, truancy, etc). "Psychopathology" included measures of several mental disorders (e.g. depression, hyperactivity, etc). Excessive Internet use was assessed as the duration and frequency of Internet use. Pathological Internet use was assessed with the Young Diagnostic Questionnaire (i.e., presence of addiction criteria). Excessive Internet use loaded on "risk-behavior" (λ = 0.484, p < .001) and on "psychopathology" (λ = 0.071, p < .007). Pathological Internet use loaded on "risk-behavior" (λ = 0.333, p < .001) and on "psychopathology" (λ = 0.852, p < .001). Chi-square tests determined that the loadings of excessive Internet use (χ2 (1) = 81.98, p < .001) were significantly stronger on "risk-behavior" than "psychopathology". Vice versa, pathological Internet use loaded significantly stronger on "psychopathology" (χ2 (1) = 107.10, p < .001). The results indicate that pathological Internet use should rather be considered as psychopathology. Excessive Internet use on the other hand, should be classified as adolescent risk-behavior.

[Relationship Between (Pathological) Internet Use and Sleep Problems in a Longitudinal Study]. / Zusammenhänge von (pathologischer) Internetnutzung mit Schlafproblemen im Längsschnitt.

Relationship Between (Pathological) Internet Use and Sleep Problems in a Longitudinal Study Excessive or pathological Internet use has already been associated with sleep disorders, but the direction of the connection remains still uncertain. The relationship between (pathological) Internet use and sleep problems in adolescence was investigated by a representative longitudinal survey of data from a sample of 1,060 students from Heidelberg and the surrounding area (SEYLE study). The students, on average 15 years old, responded at a baseline and after one year to a survey on sleep and Internet use. In addition to the number of hours of Internet use, pathological Internet use was assessed using the Young Diagnostic Questionnaire (YDQ). Sleep duration and sleep problems were surveyed by self-assessment. The prevalence of adolescents with pathological Internet use was 3.71 % in the follow-up survey. Furthermore, 20.48 % of adolescents reported sleep problems. Pathological and excessive Internet use were predictors of sleep problems over the course of one year. Adolescents who met the criteria for Internet addiction to the baseline had a 3.6 times greater risk of developing sleep problems in the course of one year. Whereas sleep problems to the baseline increased the YDQ symptoms only by 0.22. Sleep problems often occur as a result of pathological Internet use and could have an addiction-enhancing effect as well as mediating further psychiatric comorbidities. Thus, sleep problems should be targeted for early intervention and therapeutic measures.