Final answer:
Since the 1980s, cognitive psychotherapy, particularly cognitive-behavioral therapy (CBT), has gained popularity and is a well-established treatment for depression. The described study is likely a randomized controlled trial (RCT), the highest standard for testing the effectiveness of treatments in clinical psychology.
Step-by-step explanation:
Since the 1980s, the popularity of cognitive psychotherapy among clinical psychologists has increased significantly as an effective treatment for depression. Cognitive psychotherapy, also known as cognitive-behavioral therapy (CBT), takes into account cognitive processes and behaviors when providing psychotherapy. This approach has been substantiated through research and clinical practice, such as the work of Beck and colleagues on the cognitive model of depression.
The study being conducted, as described in the question, would most likely be a randomized controlled trial (RCT). An RCT is a scientific study which aims to reduce certain types of bias when testing the effectiveness of new treatments, where participants are randomly assigned to either a treatment group or a control group. This methodology is considered the gold standard in clinical research to establish the efficacy of a therapy.
In conclusion, the contribution of cognitive psychotherapy to the field of clinical psychology is crucial, providing not only a theoretical framework for understanding depression but also practical tools for treatment, which have been rigorously tested through RCTs and other research methodologies.