Long-term follow-up of a randomized controlled trial comparing acceptance and commitment therapy and standard cognitive behavior therapy for anxiety and depression.

The present study represents one of the first comparisons of the long-term effectiveness of traditional cognitive behavior therapy (i.e., Beckian cognitive therapy; CT) and acceptance and commitment therapy (ACT). One hundred thirty-two anxious or depressed outpatients were randomly assigned to receive either CT or ACT, and were assessed at posttreatment (n=90) and at 1.5-year (n=91) follow-up. As previously reported, the two treatments were equivalently effective at posttreatment according to measures of depression, anxiety, overall (social/occupational/symptom-related) functioning, and quality of life. However, current results suggest that treatment gains were better maintained at follow-up in the CT condition. Clinical significance analyses revealed that, at follow-up, one-third more CT patients were in the clinically normative range in terms of depressive symptoms and more than twice as many CT patients were in the normative range in terms of functioning levels. The possible long-term advantage of CT relative to ACT in this population is discussed.