['To investigate the frequency of gambling in people who have been diagnosed with major depressive disorder (MDD) or bipolar disorder (BD). Secondary objectives were to examine: sex differences in the rates of gambling behaviour, the temporal relation between onset of mood disorders and problem gambling, psychiatric comorbidities associated with problem gambling, and the influences of problem gambling on quality of life.', 'People (aged 18 years and older) who met criteria for lifetime Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision-defined MDD or BD I or II, and were confirmed by the Mini International Neuropsychiatric Interview, were enrolled. Participants were recruited from 5 sites in Canada and 1 in the United States. Prevalence of past-year problem gambling was assessed with the Canadian Problem Gambling Index. Associated comorbidities with problem gambling are presented.', 'A total of 579 participants were enrolled (female: n = 379, male: n = 200). Prevalence of problem gambling did not differ significantly between the MDD (12.5%) and the BD (12.3%) groups. There was a significant difference in the prevalence of problem gambling between males (19.5%) and females (7.8%) in the BD group (chi-square = 8.695, df = 1, P = 0.003). Among people meeting criteria for problem gambling, the mood disorder was the primary onset condition in 71% of cases. People with a mood disorder with comorbid current panic disorder (OR = 1.96; 95% CI 1.02 to 3.75), obsessive-compulsive disorder (OR = 1.86; 95% CI 1.01 to 3.45), specific phobia (OR = 2.36; 95% CI 1.17 to 4.76), alcohol dependence (OR = 5.73; 95% CI 3.08 to 10.65), or lifetime substance dependence (OR = 2.05; 95% CI 1.17 to 3.58), had significantly increased odds of problem gambling. Problem gambling across MDD and BD populations was also associated with lower quality of life ratings.'] Does frequency and correlate of gambling problems in outpatients with major depressive disorder and bipolar disorder?