Cognitive versus exposure therapy for problem gambling: A randomised controlled trial

Author: David Peter Smith

Smith, David Peter, 2015 Cognitive versus exposure therapy for problem gambling: A randomised controlled trial, Flinders University, School of Medicine

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Abstract

In South Australia, problem gambling is mainly a result of the widespread availability of electronic gaming machines (EGM) in venues across the state. To help lessen this problem, the Statewide Gambling Therapy Service (SGTS) offers free cognitive-behavioural therapy (CBT) and mental health care for help-seeking problem gamblers. A barrier to improving treatment delivery that clinicians faced was a lack of clear guidelines on the best gambling-specific CBT approaches. This situation prompted this research to investigate the relative efficacy of pure cognitive therapy (CT) and behavioural (exposure-based) therapy (ET). Exposure therapy targets gambling related psychobiological states (e.g. the 'urge' to gamble) and CT focuses on restructuring erroneous gambling related cognitions. A systematic literature review was first conducted to synthesise the current state of research on CT and ET approaches to problem gambling. The review suggested that trials with a lower risk bias were needed and therefore justified a further trial. The main study was a trial to compare CT and ET across a 12-week intervention period and 6-month follow-up period. It was a single-site two-group randomised, parallel design, with adult EGM problem gamblers presenting to SGTS. Primary outcome was rated by participants using the Victorian Gambling Screen (VGS) with validated cut score 21+ (score range: 0 - 60) indicative of problem gambling. All the treatment sessions were audio recorded and 20% were randomly selected and checked for therapy fidelity. Of the 87 participants who were randomised and started intervention (CT=44; ET=43), 51 completed intervention (CT=30; ET=21). Both groups experienced comparable reductions (improvement) in VGS scores at 12-weeks (CT versus ET mean difference -0.18, 95% CI: -4.48 to 4.11) and 6-month follow-up (mean difference 1.47, 95% CI: -4.46 to 7.39). Similar improvements in both interventions were also found for secondary measures. One of the main limitations of this study was loss of power due to an under representative sample size. However, compatible with the observed data, upper and lower confidence limits for estimated mean VGS differences suggested more similarities than differences between therapy groups from a clinical perspective. To explore treatment specific and non-specific effects for therapy, qualitative interviews were conducted with a sub-sample of participants. This examination revealed that all interviewees gained benefit from their respective therapies and their comments did not appear to favour one therapy over another. Both treatment specific and treatment non-specific effects were well supported as playing a therapeutic role to recovery. It was not clear as to what effect, if any, could explain most of the variability in therapeutic change. Taken together, the results showed that CT and ET were feasible and effective treatments for problem gamblers who presented to a community-based gambling therapy service in South Australia. A significant concern was the high therapy drop-out rate that was consistent with other previous trials involving psychological treatments for problem gambling. A large-scale trial is needed to compare CT and ET alone to a combined exposure-cognitive approach that can flexibly account for inter-individual variation in 'urge-cognition' experiences. A combined approach may enhance treatment retention and reduce drop-out rates.

Keywords: problem gambling,cognitive therapy,exposure therapy,randomised controlled trial
Subject: Medicine thesis

Thesis type: Doctor of Philosophy
Completed: 2015
School: School of Medicine
Supervisor: Dr Rene Pols