When depression becomes resistant, response and remission with subsequent trials of antidperessants become lesser and lesser.Effectiveness of augmentation of antidepressant medication with CBT has not been assessed as a next-step treatment option.
Nicola Wiles, Laura Thomas, Anna Abel, Nicola Ridgway, Nicholas Turner, John Campbell, Anne Garland, Sandra Hollinghurst, Bill Jerrom, David Kessler, Willem Kuyken, Jill Morrison, Katrina Turner, Chris Williams, Tim Peters & Glyn Lewis report the results of the CoBalT trial which examined the effectiveness of CBT as an adjunct to usual care including pharmacotherapy for primary care patients with treatment resistant depression compared with usual care alone.
The trial: This was a multicentre pragmatic randomised controlled trial with two parallel groups with patients recruited from family practices (primary care=general practice).Adults who had antidepressants for atleast 6 weeks but still having symptoms ( BDI score 14 or above). None had received CBT in the past 3 yrs.Participants were randomised to one of two groups: usual care or CBT in addition to usual care. Intervention group received 12 sessions of individualCBT, with (up to) a further six sessions when judged to be clinically appropriate by the therapist (maximum of 18 sessions) in addition to usual care from their general practitioner. CBT therapists used manuals for treatment and emphasis was given to formulating the psychopathology in terms of conditional beliefs. Participants were followed up 3, 6, 9, and 12 months after randomisation.
Participants: The primary outcome was BDI score at 6 months .469 patients were randomised.84% were followed up at 12 months.72% of participants were women, mean age was 50 years.45% were in paid employment.28% met criteria for severe depression.Nearly 60% had depression for 2 years or more and 70% had been on antidepressanta for more than one year.75% had a secondary diagnosis mostly anxiety disorders.43% had longlasting physical illnesses ( hypertension, diabetes,arthritis, asthma, heart disease). Mean duration of intervention was 6 months. 10% of intervention group did not attend any sessions. 32% either withdrew from therapy or were discharged due to non attendance.At 6 months, 93% of both groups were taking antidepressant medication
Results: CBT group had three-fold increased odds of response ( ie reduction in depressive symptoms score on BDI of at least 50% compared with baseline) at 6 months compared with those in the usual care group .This is an NNT of 4 for each additional patient that responded. Intervention group were also more likely to experience remission (BDI score <10) at 6 months.
Limitations: There is no attention control for treatment as usual care group. Adherence to medication was self report based.BDI, the outcome measure was used with in the sessions as well and responses on this specific measure might have been affected by the process of therapy. Resistant depression is usually defined as poor response to two antidepressants unlike in this study where participants needed to be only one agent prior to trial.
Conclusion: The size of the treatment response is substantial and is of clinical importance. Addition of CBT to antidepressants is an effective treatment strategy.
Summary of the article:
Cognitive behavioural therapy as an adjunct to pharmacotherapy for primary care based patients with treatment resistantdepression: results of the CoBalT randomised controlled trial. Wiles N, Thomas L, Abel A, Ridgway N, Turner N, Campbell J, Garland A, Hollinghurst S, Jerrom B, Kessler D, Kuyken W, Morrison J, Turner K, Williams C, Peters T, Lewis G. Lancet. 2013 Feb 2;381(9864):375-84.