This study investigates the presence of personality disorders, impulsiveness, and novelty seeking in probands with DSM-IV pathological gambling (PG), controls, and their respective first-degree relatives using a blind family study methodology. Ninety-three probands with DSM-IV PG, 91 controls, and their 395 first-degree relatives were evaluated for the presence of personality disorder with the Structured Interview for DSM-IV Personality. Impulsiveness was assessed with the Barratt Impulsiveness Scale (BIS). Novelty seeking was evaluated using questions from Cloninger’s Temperament and Character Inventory.
Results were analyzed using logistic regression by the method of generalized estimating equations to account for within family correlations. PG probands had a significantly higher prevalence of personality disorders than controls (41 vs. 7 %, OR = 9.0, P < 0.001), along with higher levels of impulsiveness and novelty seeking. PG probands with a personality disorder had more severe gambling symptoms; earlier age at PG onset; more suicide attempts; greater psychiatric comorbidity; and a greater family history of psychiatric illness than PG probands without a personality disorder. PG relatives had a significantly higher prevalence of personality disorder than relatives of controls (24 vs. 9 %, OR = 3.2, P < 0.001) and higher levels of impulsiveness. Risk for PG in relatives is associated with the presence of personality disorder and increases along with rising BIS Non-Planning and Total scale scores. Personality disorders, impulsiveness, and novelty seeking are common in people with PG and their first-degree relatives. The presence of a personality disorder appears to be a marker of PG severity and earlier age of onset. Risk for PG in relatives is associated with the presence of personality disorder and trait impulsiveness. These findings suggest that personality disorder and impulsiveness may contribute to a familial diathesis for PG.