Problematic online gambling among adolescents: A systematic review about prevalence and related measurement issues.

There is a great heterogeneity in the methodology of the reviewed studies (samples, measurement instruments, cut-off points and criteria applied). The limited number of studies and the limited generalizability of their results suggest the need for further research and for development of specific instruments to assess different levels of problematic online gambling in representative samples of adolescents based on clinical 'gold standard' criteria and more accurate cut-off points.