Insight and the number of completed modules predict a reduction of positive symptoms in an Internet-based intervention for people with psychosis

Emerging evidence suggests that Internet-based interventions for people with psychosis (ICBTp) are feasible and efficacious. However, predictors of adherence and treatment outcomes are largely unknown. To narrow this research gap, we conducted secondary analyses on data from a randomized controlled trial, which evaluated an eight-week ICBTp intervention targeting topics, such as voice hearing, mindfulness, and others. In n = 100 participants with psychosis, we aimed at identifying sociodemographic, psychopathological, and treatment-related predictor variables of post-treatment symptoms and adherence (i.e., at least four completed modules). We followed a two-stage approach. First, we conducted regression analyses to examine the effect of single candidate predictors on post-treatment symptoms as well as adherence. Subsequently, we selected variables that met a significance threshold of p < .1 and entered them into linear and logistic multiple regression models. Whereas no variable was able to predict adherence, the number of completed modules was negatively associated with self-reported delusion severity at post-treatment. Additionally, higher pre-treatment insight predicted fewer hallucinations after treatment. Because this was one of the first studies to investigate predictors in ICBTp, more research is needed to customize future interventions to the needs of users