'Robust' Evidence Supports CBT for Resistant Depression

Megan Brooks

January 22, 2016

The benefits of adding cognitive-behavioral therapy (CBT) to antidepressant therapy for patients with treatment-resistant depression last long after the CBT sessions end, according to a follow-up of the CoBalT randomized controlled trial.

"Our study provides robust evidence for the effectiveness of CBT as an adjunct to usual care that includes medication in reducing depressive symptoms and improving quality of life over the long term," study author Nicola Wiles, PhD, of the Centre for Academic Mental Health, University of Bristol in the United Kingdom, told Medscape Medical News.

"The majority of CoBalT participants had severe and chronic depression, so these results should offer hope for this population of patients. It is important that clinicians discuss referral for CBT with all those for whom antidepressants are not effective," Dr Wiles added.

The study was published online January 6 in Lancet Psychiatry.

The original trial included 469 patients with treatment-resistant depression from 73 general practices in the United Kingdom. They were assigned to continue with usual care, which included antidepressant therapy, or to receive 12 to 18 sessions of CBT in addition to usual care.

As previously reported by Medscape Medical News, patients who received CBT in addition to usual care were more than three times more likely to achieve at least a 50% reduction in depressive symptoms at 6 and 12 months than patients who continued with usual care only.

A total of 248 of the original patients (136 in the CBT group and 112 in the usual care group) participated in the follow-up study.

Scores on the Beck Depression Inventory (BDI-II) were, on average, 3.6 points lower at 46 months for patients who received CBT in comparison with those who continued with usual care (less depressed, 95% confidence interval [CI], -6.6 to -0. 6). Using data from 6, 12, and 46 months, patients in the CBT group had a mean BDI-II score that averaged 4.7 points lower (95% CI, -6.4 to - 3.0) over the 46 months compared with those in the usual care group. This equated to an effect size of 0.45 using the baseline standard deviation for BDI-II (pooled), the researchers report.

"Over 46 months, 43% of those who had received CBT in addition to usual care had improved (defined as at least a 50% reduction in depressive symptoms) compared to 27% of those who continued with usual care alone," said Dr Wiles.

Patients who received CBT in addition to antidepressant therapy had nearly threefold increased odds of response over the 46 months compared with those who did not add CBT. They were also more likely to experience remission, a reduction in anxiety, and greater improvement in scores on the Short Form–12 mental health subscale over the 46 months compared with those in the usual care group. CBT participants were also less likely to be taking antidepressants at 46 months.

"Importantly, we also found that the intervention was good value for money from the perspective of the health service," Dr Wiles said. The incremental cost-effectiveness ratio was GB£5374 (US $7687) per quality-adjusted life-year (QALY) gain. This represents a "92% probability of being cost effective at the National Institute for Health and Care Excellence QALY threshold of £20,000 [US$28607]," the authors note in their article.

"Landmark" Study

Fred Friedberg, PhD, research associate professor, Department of Psychiatry and Behavioral Science, Stony Brook University, in New York, told Medscape Medical News, "CBT is effective for depression, and this follow-up study shows that progress that people made in becoming less depressed by the end of their CBT was maintained over the long run.

"Depression is a chronic condition. It relapses and remits, so if you get sustained improvement over the long run, that's an important result to report on," said Dr Friedberg, who was not involved in the CoBalT study.

Jesse H. Wright III, MD, PhD, professor and director, Mood Disorders Division, University of Louisville School of Medicine, in Kentucky, was equally impressed.

"The CoBalT study was a landmark study, and now to have follow-up on these patients out to 5 years is almost unheard of," he noted in an interview with Medscape Medical News. "Hardly anybody is able to follow people that long. So much can happen in 5 years that the chances of there still being a discrimination between two kinds of treatment is pretty slim," which is a testament to how effective CBT is for depression," said Dr Wright, who was not involved in the study.

But access to this level of CBT in real-world populations in primary care is a problem, he noted. Delivery of computer-assisted CBT may be one solution.

"We've done several studies in mental health populations that have shown that you can greatly reduce clinician time required to get good results with computer-assisted delivery, with the physician providing guidance and support. It is a potential solution to the problem of access to the kind of therapy that is going to help people have better outcomes over the long haul," Dr Wright said.

"Having an imbedded mental health professional work in the primary care practice would also improve access to CBT, and I think there is a movement in that direction with the collaborative care model," Dr Wright noted.

The study was funded by the National Institute for Health Research Health Technology Assessment. The authors have disclosed no relevant financial relationships.

Lancet Psychiatry. Published online January 6, 2016. Full text


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