Mechanisms of change during group metacognitive therapy for repetitive negative thinking in primary and non-primary generalized anxiety disorder.

Repetitive negative thinking (RNT) is a transdiagnostic process that serves to maintain emotional disorders. Metacognitive theory suggests that positive and negative metacognitive beliefs guide the selection of RNT as a coping strategy which, in turn, increases psychological distress. The aim of this study was to test the indirect effect of metacognitive beliefs on psychological distress via RNT. Patients (N=52) with primary and non-primary generalized anxiety disorder attended a brief, six-week group metacognitive therapy program and completed measures of metacognitive beliefs, RNT, and symptoms at the first and final treatment sessions, and at a one-month follow-up. Prospective indirect effects models found that negative metacognitive beliefs (but not positive metacognitive beliefs) had a significant indirect effect on psychological distress via RNT. As predicted by metacognitive theory, targeting negative metacognitions in treatment appears to reduce RNT and, in turn, emotional distress. Further research using alternative measures at multiple time points during therapy is required to determine whether the absence of a relationship with positive metacognitive beliefs in this study was a consequence of (a) psychometric issues, (b) these beliefs only being relevant to a subgroup of patients, or (c) a lack of awareness early in treatment.