Cognitive-behavioural therapy (CBT) is less effective in treating depression than it appeared to be 40 years ago. This is the conclusion drawn from a meta-analysis of 70 studies published between 1977 and 2014. To make the comparisons more rigorous, the researchers, Tom Johnsen and Oddgeir Friborg, looked only at studies in which patients/therapists used one of the two standard scales, the Beck Depression Inventory or the Hamilton Depression Rating Scale, to rate patients’ symptoms. Over 2,426 people diagnosed with depression took part, almost two thirds of them female. The average age was 41.1
The researchers found a steady reduction in the therapy outcomes over time. Puzzled, they acknowledge that the result couldn’t be explained by an overall drop in recovery from depression, because there was no changing trend in outcomes among patients in control groups who didn’t have CBT. It was also not the case that patients in newer studies had more complex mental health problems; the reverse was, in fact, found to be so.
Two possible explanations
Reduced to speculation, Johnsen and Friborg focus on what they see as two possible explanations:
1. Inexperienced CBT practitioners:
The growing popularity of CBT has led inexperienced therapists to start using it and this might have affected outcomes, as greater experience leads to greater resolution of symptoms. Using CBT, say Johnsen and Friborg, requires “proper training, considerable practice and competent supervision”. However, outcomes were worse in trials that required CBT to be delivered as per the manual, so couldn’t be attributed, at least, to a more lackadaisical approach.
2. CBT losing its placebo effect:
Another possibility is that CBT is losing its placebo effect. The researchers comment, “In the initial phase of the cognitive era, CBT was frequently portrayed as the gold standard for the treatment of many disorders. In recent times, however, an increasing number of studies have not found this method to be superior to other techniques. Coupled with the increasing availability of information to the public, including the internet, it is not inconceivable that patients’ hope and faith in the efficacy of CBT has decreased somewhat.
“Moreover, whether widespread knowledge of the present results might worsen the situation remains an open question,” they say glumly.
(This article was first published in The Human Givens Journal, Volume 22, No 2, 2015.)
1. Johnsen, T and Friborg, O (2015). The effects of cognitive behavioral therapy as an anti-depressive treatment is falling: a meta-analysis. Psychological Bulletin, 141, 4, 747–68.↩