Gambling in youths: A new scale to measure pathological gambling behaviour.

Given the widespread of gambling among adolescents, much attention has been paid to the issue of measurement of youth gambling behaviour. Nevertheless, there is a debate about the efficiency of the most commonly employed adolescent gambling screens since current instruments are adapted from adult research and rarely encompass behaviours typically for youth. Additionally, measures based on the revised diagnostic criteria for Gambling Disorder of the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V, APA, 2013) are lacking. The aim of this study was to develop a new scale (Gambling Behavior Scale - GBS) suitable for adolescents and reflecting the DSM-V diagnostic features. Specifically, we developed the scale applying Item Response Theory (IRT) and we tested the validity of the scale with reference to sensation seeking, superstitious thinking, and gambling related cognitions. The GBS was administered to 600 past year adolescent gamblers (Mean age = 15.98, DS = 1.98). Once verified the unidimensionality of the construct through a Confirmatory Factor Analysis (CFA), IRT was applied to evaluate the functioning of the GBS along the problem gambling severity continuum. Results showed that items had different levels of severity ranging from medium to high levels and the test accurately measured medium-high gambling severity levels. Finally, the relationships between GBS scores and the related construct measures attested the validity of the GBS. Findings provide some evidence of the suitability of the GBS in measuring adolescent gambling behaviour and the accuracy of cut-off points to correctly classify at-risk and problem gamblers are discussed inside the IRT framework.