A talking control for use in evaluating the effectiveness of cognitive-behavioral therapy

Common factors predict outcome in psychotherapy, but there is a dearth of research defining and standardising control conditions. A description and evaluation of a talking control (TC) used in a randomized controlled trial (RCT) of cognitive-behavioral therapy (CBT) for older people with depression in primary care is presented.

Two hundred and four older people participated in a RCT of CBT for people with a Geriatric Mental State diagnosis of Depression (Serfaty et al., 2009). One in 10 session of CBT or TC were evaluated using the Cognitive Therapy Scale (CTS) to examine common and specific factors in therapy.

1005 therapy sessions were delivered; 508 for TC and 497 CBT. There were higher total CTS scores (P<0.001) for CBT (median 55.0; QR 52.0-55.0) than TC (median 23.0; QR 21.0-24.0). CBT scored better than TC for specific techniques (median 23.7; IQR 21.0-24.0 versus median 0.70.0; IQR 0.0-0.0, P<0.001). Both interventions scored highly for interpersonal effectiveness, but no difference was observed. The TC was easily delivered, deemed acceptable by patients and was not associated with harm.

Development, standardization and measurement of a TC intervention is possible and provides a useful comparator in evaluations of effectiveness of CBT.