Introduction Problem gambling is a public health concern affecting ∼2.3% of the Swedish population. Problem gambling also severely affects concerned significant others (CSOs). Several studies have investigated the effect of individual treatments based on cognitive–behavioural therapy (CBT), but less is known of the effect of involving CSOs in treatment. This study aims to compare an intervention based on behavioural couples therapy (BCT), involving a CSO, with an individual CBT treatment to determine their relative efficacy. BCT has shown promising results in working with substance abuse, but this is the first time it is used as an intervention for problem gambling. Both interventions will be internet-delivered, and participants will receive written support and telephone support.
Methods and analysis A sample of 120 couples will be randomised to either the BCT condition, involving the gambler and the CSO, or the CBT condition, involving the gambler alone. Measures will be conducted weekly and at 3, 6 and 12 months follow-up. The primary outcome measure is gambling behaviour, as measured by Timeline Followback for Gambling. This article describes the outline of the research methods, interventions and outcome measures used to evaluate gambling behaviour, mechanisms of change and relationship satisfaction. This study will be the first study on BCT for problem gambling.
Ethics and dissemination This study has been given ethical approval from the regional ethics board of Stockholm, Sweden. It will add to the body of knowledge as to how to treat problem gambling and how to involve CSOs in treatment. The findings of this study will be published in peer-reviewed journals and published at international and national conferences.