Addressing mental health with daily-life ecological momentary interventions (ALERT) in people at increased risk for mental disorders: a micro-randomized trial

Background: Elevated levels of distress, anxiety and depression are associated with increased risk for developing mental disorders. Ecological momentary interventions (EMIs) constitute a highly scalable, low-barrier approach for early intervention. In this study, a micro-randomized trial was conducted to investigate the proximal (short-term) and distal (longer-term) effects of different EMIs based on positive psychology, cognitive behavioral therapy (CBT), and acceptance and commitment therapy (ACT).Methods: 72 participants at increased risk for developing mental disorders comprised the sample (67.6% female). They completed a 16-day intervention phase during which they received four pre-ecological momentary assessments (pre-EMA) at semi-random moments each day assessing proximal outcomes negative (NA) and positive affect (PA). Each day, two randomly-selected pre-EMAs were immediately followed by an EMI. Thirty minutes following each pre-EMA, NA and PA were assessed again. Before and after the intervention phase, distal outcomes symptoms of depression, anxiety and well-being were assessed.Results: Multilevel models showed proximal improvements in PA following EMIs based on positive psychology and ACT. NA decreased following positive psychology; ACT specifically improved NA during moments of higher NA at pre-EMA. The CBT-based EMI neither improved NA nor PA. Distal improvements in symptoms of depression, anxiety and well-being were observed.Discussion: This study provides support for the beneficial immediate effects of EMIs based on positive psychology and ACT on affect; symptoms of psychopathology and well-being improved on a distal level. Future research should further investigate the benefits of different EMIs in crucial moments (e.g., high momentary NA) to develop adequate just-in-time support.