Adolescent Pathological Gambling: Using IRT to Construct a Scale Based on the New Gambling Disorder Criteria

Introduction: Given the widespread of gambling among adolescents, much attention has been paid to the issue of measurement of youth gambling problems. Nevertheless, there is a debate about the efficiency of the most commonly employed adolescent gambling screens, 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, American Psychiatric Association, 2013) are lacking, and there is a general lack of Item Response Theory (IRT) studies on problem gambling severity measures. Objectives: The aim of this study was to develop a new scale (Gambling Behavior Scale - GBS) to measure pathological gambling behavior. Specifically, we aimed to develop items reflecting the DSM-V diagnostic features and to apply IRT in order to examine the instrument’s accuracy along problem gambling severity levels. The validity of the scale was studied with reference to school achievement, quality of life, risk seeking behaviors, and superstitious thinking. Design/Methodology: The GBS was administered to 249 adolescent past year gamblers (Male = 54%, Mean age=17.55, SD=.50). Results: The unidimensionality of the construct, a fundamental criterion underlying IRT models, was assessed through a Confirmatory Factor Analysis (CFA), IRT was applied to evaluate the functioning of the GBS along the problem gambling severity continuum. Item parameter estimates and the test information function showed that each item and the global scale satisfactorily measured the latent trait. Specifically, items had different levels of severity ranging from medium to high values and the test accurately measured medium-high gambling severity levels. Finally, evidence of the validity of the GBS was provided examining the relationships between problem gambling and the related constructs. Conclusion: These findings provide evidence of the GBS’s adequacy for assessment of adolescent problem gambling indicating that it satisfactorily measures different levels of the underlying construct.