Written by Paulo Knapp, PhD
A systematic review of the literature of all published papers in the year of 2014 describing randomized controlled trials (RCTs) that compared cognitive-behavioral interventions with a wait-list control group, or another form of psychosocial intervention or other medical treatment was conducted. Only RCTs that clearly specified a CBT theoretical orientation were included. Samples included all populations, undergoing any type of psychiatric or medical condition; subjects with no formal diagnosis (e.g., students in a school-based prevention program), and psychotherapy professionals in training condition were also included. As the objective of the review was to take an instant picture of the current clinical applications of CBT interventions in the whole spectrum of psychiatric and other medical disorders, variables such as fidelity of therapists to the proposed intervention, heterogeneity of the experimental samples, appropriateness of the control groups, and any other confounding variables were not analyzed.
The data extracted from 394 identified RCTs published in the year of 2014 revealed that around 58,000 individuals underwent CBT-based interventions conducted in 34 countries for the treatment of 22 different medical and psychiatric diagnoses. As could be expected, the most prevalent investigated diagnosis was depressive disorders in 20% of trials, while other medical conditions, as chronic pain and fatigue, and collateral symptoms of cancer treatments, e.g., insomnia, were treated with cognitive-behavioral interventions in 75 studies, 19% of total. Among other diagnosis, mixed anxiety-depression symptoms were addressed in 63 studies, and substance use disorders in 37 studies.
One hundred forty seven trials were conducted in the USA, and 15 in Canada, summing up 162 (41% of total) studies in North America. European countries showed a similar contribution with 167 (43% of total) studies, mostly from United Kingdom (43), The Netherlands (35), Germany (25), and Sweden (21), representing three quarters of the European trials. Outside North America and Europe, Australia published a fair amount of studies (35), and CBT-oriented trials were also reported with samples far apart in the globe as China (9) and Brazil (4), as well as in different countries like Israel, Pakistan, Iran, Congo, Indonesia, Turkey, Korea, India, and Greece, among others. However, almost all (95% of total) trials were conducted in high-income economy countries.
In accordance to our current times, 65 (16.5%) studies reported web-based cognitive-behavioral interventions, from Internet sites to phone apps. Four studies conducted in school settings aiming psychopathology prevention were published, as well as two trials comparing different formats and settings for professional training in CBT.
This systematic review shows that there has been a steady dissemination and adoption of the cognitive-behavioral therapies in practitioner’s clinical work in a wide array of psychiatric and medical conditions. The high number of randomized clinical trials conducted in a single year, with worldwide study samples, reporting an increasingly widespread use for different clinical conditions, demonstrates a definite consolidation of cognitive behavioral therapies in the contemporary therapeutic scene.