Randomized controlled trial of a modular, transdiagnostic, cognitive-behavioral anxiety intervention versus primary care behavioral health treatment as usual.

Offering behavioral treatment for anxiety in primary care will help to address the anxiety treatment gap. Modular Anxiety Skills Training (MAST) is a transdiagnostic cognitive-behavioral therapy (CBT) intervention for Primary Care Behavioral Health (PCBH) settings. This multi-site randomized controlled trial compared the effects of MAST versus PCBH treatment as usual (TAU), both delivered by frontline clinicians, on anxiety severity and impairment. Participants (N = 167, 70% male, 89% White, 9% Hispanic, M age 51 [16] years) were recruited from primary care at two Veterans Health Administration healthcare systems. Contrary to our hypothesis, intent-to-treat analyses found no differences by condition at 16-weeks post-treatment. Participants in both conditions improved significantly on overall anxiety severity and impairment (OASIS) as well as anxiety and depression symptom severity, functional disability, and quality of life, with small to medium effect sizes (0.21-0.61). All gains were maintained at 28-week follow-up, and participants receiving MAST demonstrated further significant reduction in OASIS. Post hoc analyses suggested baseline depression severity moderated the condition effect; participants with moderate and severe comorbid depression responded better to MAST than PCBH TAU. While MAST was not superior to PCBH TAU at post-treatment as hypothesized, it may potentially yield a more enduring impact and work better with comorbid depression; however, these findings require prospective replication. This study advances the literature by comparing brief CBT for anxiety in primary care to a strong active comparison comprising behavioral treatment. MAST may offer implementation advantages due to being manualized and modular. Further research on modular CBT for anxiety is warranted.