Protocol for the Parent Anxiety Transmission and Habits (PATH) study: a randomised controlled trial testing parent interpretation bias as a key mechanism of intergenerational transmission of anxiety.

introductionAnxiety disorders are the most common youth mental health problems in the USA. Most children do not receive treatment and among the few who do, many do not experience significant improvement. Thus, there is an urgent need to identify novel intervention targets to improve treatments for childhood anxiety. Past research demonstrates that parent anxiety plays a role in the development and maintenance of child anxiety, but empirical evidence for the mechanisms that drive this transmission is lacking. Interpretation bias, or the tendency to perceive threat in ambiguous situations, may lead parents to engage in anxiety-promoting parenting behaviours, which may transfer this cognitive bias to their children, resulting in youth anxiety. Given the current lack of empirical evidence supporting this theorised mechanism, the present study will test effects of parent interpretation bias on parent behaviour and child interpretation bias. Our central hypothesis is that parent interpretation bias influences child interpretation bias through its effects on anxiety-promoting parenting behaviours. The study will also evaluate potential moderators of these theorised relationships, such as parent sex, race and ethnicity, parent anxiety, child age and child sex. METHODS AND ANALYSIS: We will randomise 300 parents of children aged 7-12 to a smartphone app-delivered interpretation bias manipulation condition or a self-assessment control condition. Through a series of study assessments over the course of 3 months, parents and children will complete self-report, interview, behavioural and daily diary measures to assess the primary proximal outcome (anxiety-promoting parenting behaviours), the secondary distal outcome (child interpretation bias) and moderators. To test our central hypothesis, we will first use hierarchical linear modelling to assess whether parents in the interpretation bias manipulation condition show fewer anxiety-promoting parenting behaviours compared with control, and whether children of those parents show improved interpretation bias compared with control. We will then implement mediation models to evaluate whether a reduction in anxiety-promoting parenting behaviours mediates the association between parent and child interpretation bias. ETHICS AND DISSEMINATION: Ethical approval for this study was granted by the Mass General Brigham Institutional Review Board (2022P003245). We will disseminate the results of this study to the scientific community, clinical community and the public through several channels such as peer-reviewed publications in scientific journals, national conferences, hospital lectures, press releases and TRIAL REGISTRATION NUMBER: NCT05665491.