Evidence of an increased risk for various psychiatric disorders among pathological gamblers far exceeds our understanding of the impact that this psychiatric comorbidity has on the outcome of treatment for pathological gambling. One major source of the problem is that treatment efficacy and effectiveness studies for pathological gambling typically have not addressed comorbidity's impact on outcome. This paper discusses epidemiological, clinical, health service delivery, and research issues pertaining to the intersection of pathological gambling treatment outcome and comorbid psychiatric disorders. It is argued that this topic suffers from major knowledge gaps in terms of the nature of comorbidity of pathological gambling and other psychiatric disorders and the role of client characteristics on treatment outcome for pathological gambling. Research priorities are identified.
