Objective: The aim of this paper was to systematically review and meta-analyse the prevalence of co-morbid psychiatric disorders (DSM-IV Axis I disorders) among treatment-seeking problem gamblers. Methods: A systematic search was conducted for peer-reviewed studies that provided prevalence estimates of Axis I psychiatric disorders in individuals seeking psychological or pharmacological treatment for problem gambling (including pathological gambling). Meta-analytic techniques were performed to estimate the weighted mean effect size and heterogeneity across studies. Results: Results from 36 studies identified high rates of co-morbid current (74.8%, 95% CI 36.5–93.9) and lifetime (75.5%, 95% CI 46.5–91.8) Axis I disorders. There were high rates of current mood disorders (23.1%, 95% CI 14.9–34.0), alcohol use disorders (21.2%, 95% CI 15.6–28.1), anxiety disorders (17.6%, 95% CI 10.8–27.3) and substance (non-alcohol) use disorders (7.0%, 95% CI 1.7–24.9). Specifically, the highest mean prevalence of current psychiatric disorders was for nicotine dependence (56.4%, 95% CI 35.7–75.2) and major depressive disorder (29.9%, 95% CI 20.5–41.3), with smaller estimates for alcohol abuse (18.2%, 95% CI 13.4–24.2), alcohol dependence (15.2%, 95% CI 10.2–22.0), social phobia (14.9%, 95% CI 2.0–59.8), generalised anxiety disorder (14.4%, 95% CI 3.9–40.8), panic disorder (13.7%, 95% CI 6.7–26.0), post-traumatic stress disorder (12.3%, 95% CI 3.4–35.7), cannabis use disorder (11.5%, 95% CI 4.8–25.0), attention-deficit hyperactivity disorder (9.3%, 95% CI 4.1–19.6), adjustment disorder (9.2%, 95% CI 4.8–17.2), bipolar disorder (8.8%, 95% CI 4.4–17.1) and obsessive-compulsive disorder (8.2%, 95% CI 3.4–18.6). There were no consistent patterns according to gambling problem severity, type of treatment facility and study jurisdiction. Although these estimates were robust to the inclusion of studies with non-representative sampling biases, they should be interpreted with caution as they were highly variable across studies. Conclusions: The findings highlight the need for gambling treatment services to undertake routine screening and assessment of psychiatric co-morbidity and provide treatment approaches that adequately manage these co-morbid disorders. Further research is required to explore the reasons for the variability observed in the prevalence estimates.

This study provides a systematic review of the empirical evidence related to the association between problem gambling and intimate partner violence (IPV). We identified 14 available studies in the systematic search (8 for victimisation only, 4 for perpetration only and 2 for both victimisation and perpetration). Although there were some equivocal findings, we found that most of the available research suggests that there is a significant relationship between problem gambling and being a victim of IPV. There was more consistent evidence that there is a significant relationship between problem gambling and perpetration of IPV. Meta-analyses revealed that over one third of problem gamblers report being victims of physical IPV (38.1%) or perpetrators of physical IPV (36.5%) and that the prevalence of problem gambling in IPV perpetrators is 11.3%. Although the exact nature of the relationships between problem gambling and IPV is yet to be determined, the findings suggest that less than full employment and clinical anger problems are implicated in the relationship between problem gambling and IPV victimization and that younger age, less than full employment, clinical anger problems, impulsivity, and alcohol and substance use are implicated in the relationship between problem gambling and IPV perpetration. The findings highlight the need for treatment services to undertake routine screening and assessment of problem gambling, IPV, alcohol and substance use problems, and mental health issues and provide interventions designed to manage this cluster of comorbid conditions. Further research is also required to investigate the relationship between problem gambling and violence that extends into the family beyond intimate partners.