This package contains the datasets and syntax files associated with the submitted manuscript 'Group autonomy enhancing treatment versus cognitive behavioral therapy for anxiety disorders: A cluster-randomized clinical trial', published in Depression and Anxiety (2022).

Background: Although cognitive behavioral therapy (CBT) is effective in the treatment of anxiety disorders, few evidence-based alternatives exist. Autonomy enhancing treatment (AET) aims to decrease the vulnerability for anxiety disorders by targeting underlying autonomy deficits and may therefore have similar effects on anxiety as CBT, but yield broader effects.

Methods: A multicenter cluster-randomized clinical trial was conducted including 129 patients with DSM-5 anxiety disorders, on average 33.66 years of age (SD = 12.57), 91 (70.5%) female, and most (92.2%) born in the Netherlands. Participants were randomized over 15-week groupwise AET or groupwise CBT and completed questionnaires on anxiety, general psychopathology, depression, quality of life, autonomy-connectedness and self-esteem, pre-, mid-, and posttreatment, and after 3, 6, and 12 months (six measurements).

Results: Contrary to the hypotheses, effects on the broader outcome measures did not differ between AET and CBT (d = .16 or smaller at post-test). Anxiety reduction was similar across conditions (d = .059 at post-test) and neither therapy was superior on long term.

Conclusion: This was the first clinical randomized trial comparing AET to CBT. The added value of AET does not seem to lie in enhanced effectiveness on broader outcome measures or on long term compared to CBT. However, the study supports the effectiveness of AET and thereby contributes to extended treatment options for anxiety disorders.

Pregistration: The study protocol was preregistered in the Dutch Trial Registry (https://trialsearch.who.int/Trial2.aspx?TrialID=NTR6473)