Does baseline psychiatric symptom severity predict well-being improvement in low-intensity mindfulness interventions?

Regardless of baseline psychiatric symptom severity, individuals can improve from psychotherapy, including from low-intensity psychosocial treatments. We conducted a secondary analysis of a randomized trial of low-intensity mindfulness interventions to explore if and how specific indices of baseline symptom severity were associated with well-being trajectories during treatment and follow-up. In the original study, participants (N = 4, 411) with physical and mental health conditions were randomly assigned to one of two low-intensity mindfulness interventions (eight-session mindfulness-based cognitive therapy or a three-session mindfulness intervention). In this secondary analysis, we pooled across treatment groups and stratified participants into subgroups based on self-reported baseline levels of anxiety, depression, and social functioning. We used linear mixed effects models and descriptive trajectory plots to evaluate differences in well-being trajectories between subgroups. Baseline symptom severity was associated with well-being trajectory such that those with more severe anxiety, depression, or social functioning at baseline had generally lower well-being across time. All subgroups experienced initial improvement in well-being during the treatment period, though individuals with worse symptom severity tended not to sustain improvements and rebounded back towards baseline well-being levels during follow-up. These data suggest that, for individuals with more severe mental health symptoms, eight or three-session mindfulness-based interventions may still be clinically useful (as patients with more severe symptoms in this study were able to experience initial improvement in well-being from such interventions). However, for such patients, offering these mindfulness-based interventions for a longer duration may have prevented symptom rebounding.