Psychological therapies for pathological and problem gambling

Abstract

Various psychological therapies for pathological and problem gambling have been evaluated in randomised trials. A synthesis of best-quality evidence is required. The objective was to synthesise evidence from randomised trials of psychological therapies for pathological and problem gambling (cognitive-behaviour therapy (CBT), motivational interviewing therapy, integrative therapy, other psychological therapy), in order to indicate the efficacy of therapies and durability of therapy effects, relative to control conditions. We conducted a search of the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR), which includes relevant randomised controlled trials from the following bibliographic databases: CENTRAL (The Cochrane Central Register of Controlled Trials) (all years), EMBASE (1974 -), MEDLINE (1950 -) and PsycINFO (1967 -). We also carried out complementary searches of MEDLINE, EMBASE, PsycINFO, LILACS and CENTRAL for studies published between January 1980 and October 2011. We examined the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov and also conducted manual searches of selected journals and reference lists of included studies. Included studies were clinical trials using random allocation to groups, considering pathological or problem gamblers, and evaluating a psychological therapy for pathological or problem gambling. Control conditions included 'no treatment' controls, referral to Gamblers Anonymous and non-specific treatment component controls. We systematically extracted data on the characteristics and results of studies. Primary outcomes were measures of gambling symptom severity, financial loss from gambling and frequency of gambling. Secondary outcomes were occurrence of pathological gambling diagnoses and depression and anxiety symptoms. Treatment effects were defined by comparisons between therapy and control conditions at post-treatment assessments (conducted from 0 to 3 months following completion of treatment) and follow-up assessments (conducted from 9 to 12 months following completion of treatment), respectively, using the standardised mean difference (SMD) or risk ratio (RR). We synthesised results through random-effects meta-analysis. Fourteen studies (n = 1245) met the inclusion criteria. Eleven studies compared CBT with control and comparisons at 0 to 3 months post-treatment showed beneficial effects of therapy that ranged from medium (when defined by financial loss from gambling: SMD -0.52; 95% confidence interval (CI) -0.71 to -0.33, n = 505) to very large (for gambling symptom severity: SMD -1.82; 95% CI -2.61 to -1.02, n = 402). Only one study (n = 147) compared groups at 9 to 12 months follow-up and produced smaller effects that were not significant. Four studies of motivational interviewing therapy were identified and mainly considered samples demonstrating less severe gambling (relative to studies of pathological gamblers). Data suggested reduced financial loss from gambling following motivational interviewing therapy at 0 to 3 months post-treatment (SMD -0.41; 95% CI -0.75 to -0.07, n = 244), although comparisons on other outcomes were not significant. The effect approached zero when defined by gambling symptom severity (SMD -0.03; 95% CI -0.55 to 0.50, n = 163). Studies compared groups at 9 to 12 months follow-up and found a significant effect of motivational interviewing therapy in terms of frequency of gambling (SMD -0.53; 95% CI -1.04 to -0.02, n = 62), with comparisons on other outcomes that were not significant. Two studies of integrative therapies also considered samples demonstrating overall low gambling severity, and found no significant effects of therapy at 0 to 3 months post-treatment. Comparisons at 9 to 12 months follow-up suggested a medium effect from therapy in terms of gambling symptom severity, with no significant differences for other outcomes. One study (n = 18) considered another psychological therapy (i.e.Twelve-Step Facilitated Group Therapy) and suggested beneficial effects in terms of most outcomes at 0 to 3 months post-treatment. The evidence supporting these various classes of therapy ranged from very low to low quality. This review supports the efficacy of CBT in reducing gambling behaviour and other symptoms of pathological and problem gambling immediately following therapy.