To determine the clinical effectiveness of Cognitive Behaviour Therapy (CBT) delivered in primary care for older people with depression and evaluation of a talking control (TC).

A single-blind, randomized, controlled trial with 4- and 10-month follow-up. 204 people, aged 65 years or more, with a Geriatric Mental State diagnosis of depression were recruited from primary care. The interventions were: treatment as usual (TAU), TAU plus TC, or TAU plus CBT. The TC and CBT were offered over 4 months. The TC was to control for common effects in therapy. The Beck Depression Inventory-II (BDI-II) was the main outcome. Subsidiary measures were the Beck Anxiety Inventory, Social Functioning Questionnaire, and Euroqol. Intention to treat analysis (ITT) and Compliance Average Causal Effect (CACE) analyses was employed. The Cognitive therapy scale (CTS) evaluated common and specific factors in therapy.

A mean of 7 sessions of TC or CBT were delivered. ITT analysis found improvements of −3.07 (95% confidence interval [CI], −5.73 to −0.42) and −3.65 (95% CI, −6.18 to −1.12) in BDI-II scores in favour of CBT vs TAU and TC respectively. CACE analysis found a benefit of 0.4 points (95% CI, 0.01 to 0.72) per therapy session of CBT over TC. Ratings for CBT on the CTS were high (mean [SD], 54.2 [4.1]) and showed no difference for nonspecific, but significant differences for specific factors in therapy.

CBT is an effective treatment for depressed older people. Improvement appears to be associated with specific factors in CBT.