Personality and problem gambling: a prospective study of a birth cohort of young adults

CONTEXT: Individual differences in dimensions of personality may play an important role in explaining risk for disordered gambling behavior as well as the comorbidity between disordered gambling behavior and other substance-related addictive disorders. OBJECTIVES: To identify the personality correlates of problem gambling in a representative non-treatment-seeking sample, as well as to determine whether these are similar to the personality correlates of other substance-related addictive disorders and whether individual differences in personality might account for the comorbidity between disordered gambling behavior and other substance-related addictive disorders. DESIGN: Longitudinal population-based study. PARTICIPANTS: A complete birth cohort of young adults born in Dunedin, New Zealand, between April 1, 1972, and March 31, 1973 (N = 939; 475 men, 464 women). MAIN OUTCOME MEASURES: Multidimensional Personality Questionnaire assessments of personality were obtained at age 18 years; structured interview-based diagnoses of past-year problem gambling and alcohol, cannabis, and nicotine dependence were obtained at age 21 years. RESULTS: Problem gambling at age 21 years was associated with higher scores on the higher-order personality dimension of negative emotionality (d = 0.90) and with lower scores on the personality dimension of constraint (d = -0.72) measured at age 18 years compared with control subjects who did not have a past-year addictive disorder at age 21 years. Problem gambling was also associated with Multidimensional Personality Questionnaire indicators of risk-taking (d = 0.50) and impulsivity (d = 0.56). The personality profile associated with problem gambling was similar to the profiles associated with alcohol, cannabis, and nicotine dependence. The relations between problem gambling and the substance-related addictive disorders (odds ratios = 3.32-3.61) were reduced after controlling for individual differences in personality (odds ratios = 1.90-2.32). CONCLUSIONS: From the perspective of personality, problem gambling has much in common with the addictive disorders, as well as with the larger class of "externalizing" or "disinhibitory" disorders. Knowledge gained from the study of common personality underpinnings may be helpful in determining where disordered gambling behavior should reside in our diagnostic classification system.