Metacognitive Therapy (MCT) targets maladaptive metacognitions and the cognitive attentional syndrome (CAS) (Wells 2009). Transdiagnostic interventions are increasingly encouraged to address comorbidity efficiently and to improve cost-effectiveness (McEvoy et al. 2009). However, structured brief group protocols with long-term follow-up remain limited.

This pilot study developed and tested an 8-session manualized transdiagnostic group MCT protocol for adults with mixed anxiety and depressive symptoms, examining both immediate and 6-month outcomes.

Twelve participants (gathered from 3 groups) completed the intervention. The protocol included detached mindfulness, attention training, and modification of maladaptive beliefs. Outcomes were assessed at baseline, post-treatment, and 6-months: Clinical Global Impressions Severity (CGI-S), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), CAS-1, and Outcome Rating Scale (ORS). Within-group analyses were performed with paired tests.

Significant pre- to post-treatment improvements were observed across all primary measures, with large to very large effect sizes (Table 1). At 6-month follow-up, reductions in depression, anxiety, and CAS, and improvements in functioning were maintained. Comparisons between post-treatment and follow-up were not significant (p = 0.191–0.949), suggesting stability of gains.Table 1.

Key outcomes (Mean ± SD) and effect sizes

Structure of the 8-Session Transdiagnostic MCT Protocol

An 8-session transdiagnostic MCT group protocol was feasible, well accepted, and associated with robust reductions in distress, maladaptive metacognitions, and CAS, alongside improvements in functioning. Gains were sustained at 6 months, with no significant decline or further improvement, highlighting stability of effects. Despite encouraging outcomes, the small and uncontrolled nature of this study limits generalizability. Larger randomized controlled trials are required.

None Declared