Gambling Harm Treatment and Support in Scotland: Current provisions and future directions

Chapter 3: Evidence on the effectiveness of gambling harm interventions

3.1 A public health framework for understanding intervention effectiveness

The evidence on gambling harm interventions must be understood within a broader public health framework. As the Lancet Public Health Commission on Gambling demonstrated, the prevention and reduction of gambling harms cannot be achieved through treatment and support services alone. Rather, it requires a combination of universal, selective and targeted interventions, operating across multiple levels of the system. This position is echoed by Public Health Scotland (PHS), who emphasise that gambling harms cannot be addressed by healthcare services alone, but require attention to the environments in which gambling occurs, the role of industry practices, and broader social and economic conditions which shape vulnerability to harm.

Whilst this project is rooted in this wider perspective, understanding the effectiveness of specific interventions with respect to gambling treatment and support remains important, including a range of targeted and selective interventions. See Table 1 starting on page 16, which also includes information about the availability of each intervention in Scotland.

3.2 Key updates to the evidence base

Table 1 shows a range of interventions for gambling harms and treatment that were included in both the Lancet Public Health Commission on Gambling (LPHCG) and the PHS assessment. The table provides an update on likely efficacy based on the review of recent evidence. This process indicates that there have been no major changes in the overall structure of the evidence base since 2024. The relative distribution of evidence across intervention types remains broadly consistent.

Interventions for which there is a strong evidence base supporting effectiveness include cognitive behavioural therapy (CBT), internet-based CBT (I-CBT), and mandatory limit-setting. CBT is supported by consistent evidence demonstrating its effectiveness in reducing gambling harms and is recommended by NICE as both an effective and cost-effective approach (recommendations 1.5.13-1.5.15). I-CBT extends this approach through remote/online delivery, albeit with higher rates of attrition. Mandatory limit-setting, where limits on spending or play time are imposed rather than voluntarily chosen, has also been shown to reduce harm by constraining high-risk behaviour at the point of consumption.

A second group of interventions is supported by sufficient evidence, but with relatively small effects. These include brief interventions, self-help approaches and mutual support groups. Brief interventions, typically short, structured conversations or sessions that could be provided by non-specialists, can reduce harm but are less effective than longer-term, structured treatments. Self-help interventions, such as online tools or guided materials, show modest benefits compared to no intervention. Similarly, mutual support groups (including peer-led models) are associated with positive outcomes but the overall effect size is small.

A further set of interventions demonstrates potential efficacy, although the evidence is more mixed and often contingent on implementation. These include self-exclusion, interventions based on behavioural tracking, and personalised feedback incorporating motivational interviewing (MI) techniques^[17], and educational interventions and approaches aimed at priming analytical thinking. The former three of these interventions are enabled by the wider legislative and regulatory environment, for example, through mandated self-exclusion systems or requirements on operators to monitor and respond to risky behaviour, and therefore sit largely outside the direct control of individual service providers. The updated assessment also incorporates recent critiques of industry-funded educational interventions in the UK, which raise questions about both their effectiveness and underlying rationale.

Voluntary limit-setting is generally considered to be mostly ineffective. This approach relies on individuals setting their own limits on gambling expenditure or time, but the evidence suggests that such limits are frequently not adhered to, particularly among those experiencing higher levels of harm.

Finally, there are interventions for which the evidence remains inconsistent or insufficient. Providing details of helplines, while an important component of broader support systems, has not been shown to produce consistent behavioural change in isolation. Pharmacological treatments also fall into this category, with no conclusive evidence supporting a specific medication for gambling disorder. However, NICE guidelines (1.5.16-1.5.19) indicate that naltrexone may be considered in certain cases alongside psychological interventions, particularly where these have not been effective or where relapse has occurred.

The updated evidence synthesis provides a framework for interpreting current service provision in Scotland.