Patients with treatment-resistant depression who receive cognitive-behavioral therapy (CBT) in addition to antidepressants over several months may continue to benefit from the therapy years later, according to a study in Lancet Psychiatry.
While previous studies have reported the effectiveness of CBT for people with treatment-resistant depression, the new findings support the long-term effectiveness of the therapy.
As previously described, researchers at the University of Bristol in the United Kingdom randomly assigned 469 patients aged 18 to 75 with treatment-resistant depression to receive usual care or 12 to 18 sessions of CBT in addition to usual care. Participants in the CoBalT trial included those from multiple general practices in the United Kingdom who had been taking antidepressants for six or more weeks, had Beck Depression Inventory [BDI-II] scores of greater than or equal to 14, and met ICD-10 depression criteria. Six months after the CBT sessions ended, 46% of the intervention group met the criteria for response (at least a 50% reduction in depressive symptoms from baseline) compared with 22% in the usual care group.
In the current study, the researchers followed up with the participants in the original trial and asked them to complete a questionnaire, which included questions about depressive symptoms and other physical and psychological comorbidities, over a period of three to five years.
Of the 248 individuals who completed the long-term follow-up questionnaire, 197 participants (72%) reported taking antidepressants since the initial trial, but sustained use of antidepressants was lower in the intervention group than in the usual care group (101 [68%] in the intervention group vs 96 [76%] in the usual care group).
Individuals in the intervention group had a BDI-II score that was, on average, 3.6 points lower than that of the usual care group at 46 months. Additional analysis revealed that participants in the intervention group had nearly a threefold increased odds of response over the 46 months compared with those in the usual care group. Among other differences, those in the intervention group were also more likely to experience remission (BDI-II score less than 10) and a reduction in anxiety over the 46 months compared with those in the usual care group.
“Our findings provide robust evidence for the effectiveness of CBT given as an adjunct to usual care that includes medication in reducing depressive symptoms and improving quality of life over the long term,” the study authors wrote. “As most of the CoBalT participants had severe and chronic depression, with physical or psychological comorbidity, or both, these results should offer hope for this population of difficult-to-treat patients.”
For related information, see the Psychiatric News article “Integrating CBT, Pharmacotherapy May Prevent Relapse in MDD” and the Psychiatric Services article “Organized Self-Management Support Services for Chronic Depressive Symptoms: A Randomized Controlled Trial.”