Mental contrasting as a health behaviour change technique: a systematic review and meta-analysis

Abstract

Background: Mental contrasting is a self-regulation strategy required for strong goal commitment. Mental contrasting involves: (1) imagining a desired future health goal (2) contrasting the goal with the reality proceeding the goal state, which after reflection is viewed as an obstacle (Oettingen et al., 2000). Recent research has also used implementation intentions (MCII), which is hypothesised to strengthen the effects. Methods: A systematic review (PROSPERO reference: CRD42016034202) was conducted to evaluate the effectiveness of mental contrasting for improving health-related behaviours in adult populations, compared with control/active control groups. Findings: Searches identified eleven studies (1384 participants) reporting mental contrasting techniques for promoting healthy behaviours (e.g. increasing physical activity or fruit and vegetable intake) and reducing unhealthy behaviours (e.g. smoking, unhealthy snacking) across clinical, student and general populations. A meta-analysis using random effects modelling found a main effect of mental contrasting on health outcomes, adjusted Hedges’ g = 0.28 (standard error .07) CI (0.12-0.43 p<0.001) at up to four weeks, and 0.32, CI (0.18-0.47), p<0.001 at over 3 months (n=4). MCII (n=5) showed a similar effect, g = 0.27, CI (0.12-0.43), p<0.001, to mental contrasting. Discussion Mental contrasting shows promise as a brief behaviour change technique with significant small to moderate-sized effect on changing health behaviour in the short term. The benefits of mental contrasting appear to be sustained over time. Analysis on a small subset of studies suggested that the addition of implementation intentions (MCII) did not strengthen the effects of mental contrasting on health behaviours, although additional studies are needed.