Prevalence of psychiatric co-morbidity in treatment-seeking problem gamblers: A systematic review and meta-analysis.
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.
School of Psychology, Deakin University, Burwood, VIC, Australia Melbourne Graduate School of Education, University of Melbourne, Melbourne, VIC, Australia School of Psychological Sciences, Monash University, Melbourne, VIC, Australia Centre for Gambling Research, Australian National University, Canberra, ACT, Australia nicki.dowling@deakin.edu.au.
Nicki A
NA
Dowling
School of Social and Community Medicine, Bristol University, Bristol, UK.
Sean
S
Cowlishaw
Melbourne Graduate School of Education, University of Melbourne, Melbourne, VIC, Australia.
Alun C
AC
Jackson
School of Psychology, Deakin University, Burwood, VIC, Australia Problem Gambling Research and Treatment Centre, Monash University, Melbourne, VIC, Australia.
Stephanie S
SS
Merkouris
Melbourne Graduate School of Education, University of Melbourne, Melbourne, VIC, Australia.
Kate L
KL
Francis
Melbourne Graduate School of Education, University of Melbourne, Melbourne, VIC, Australia Faculty of Health Sciences, University of Lethbridge, Lethbridge, AB, Canada.
Darren R
DR
Christensen
D000437:Alcoholism / Q000453:epidemiology / Q000523:psychology; D001008:Anxiety Disorders / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D005715:Gambling / Q000453:epidemiology / Q000523:psychology*; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology* / Q000523:psychology; D019964:Mood Disorders / Q000453:epidemiology / Q000523:psychology; D015995:Prevalence; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000523:psychology
Gambling; co-morbidity; meta-analysis; psychiatric disorders; systematic review