Psychotherapy over the Last Four Decades
The major catalyst for psychotherapy efficacy research was the psychiatric pharmacologic revolution. Rating scales to test efficacy regarding a range of psychiatric symptoms, along with diagnostic interviews to better define patient populations, were developed to test the new psychotropic drugs. Patient deinstitutionalization and the increase in ambulatory psychiatric care, fueled by the community health center movement, required measures of community functioning that took into account more than mere symptoms. Assessments that measured family, work, and interpersonal relationships were developed and became one target for psychotherapy outcome studies. While medications were being widely tested, psychotherapy was, in practice, the most common treatment for major depression and other psychiatric disorders. The conventional wisdom among both psychopharmacologists and psychotherapists was that one could not test the efficacy of psychotherapy. The effects were believed to be the product of each individual therapist’s own skills. There was disagreement as to the value of drugs or psychotherapy. Some felt that psychotherapy would undo the good effects of medication, and others felt that medication would divert the patient from dealing with the personality problems that produced their symptoms. Eysenck’s view of psychotherapy2 was popular. Based on 7000 cases from studies of psychoanalysis and other forms of psychotherapy, he concluded that there was no evidence for their efficacy. In the late 1960s, not one psychotherapy clinical trial that used a randomized design and standardized assessments was published. This is no surprise; it was only in 1962, with the passage of the Kefauver-Harris amendment, that the Food and Drug Administration (FDA) required substantial efficacy data for the approval of new medications.
It was in this context that Aaron Beck and Gerald Klerman—psychiatrists and also friends—independently began writing manuals with scripts in what were later called cognitive-behavioral therapy (CBT) and interpersonal psychotherapy (IPT), respectively. These manuals were used to train therapists and to carry out the first randomized psychotherapy clinical trials. By 1979, the trials had flourished, and 17 clinical trials were identified testing the efficacy of behavioral, cognitive, group, marital, or interpersonal psychotherapy alone, in comparison to, and in combination with, pharmacotherapy in homogenous samples of depressed outpatients.3
In the mid 1980s, a large, multisite clinical trial was launched by the National Institute of Mental Health to test the efficacy of CBT, IPT, imipramine, and placebo for treating depression.4 This study included two years’ preliminary work to establish and test both manual-guided training and the procedures for determining fidelity in the clinical trial. The methods developed for that trial were the precursors of the methods used today for training and for ensuring fidelity in psychotherapy trials.5 With the growth of psychotherapy testing, London and Klerman6 suggested that an FDA for psychotherapy be established to review psychotherapies and determine that the evidence from clinical trials was sufficient to justify clinical use. This did not happen.
What’s the current status of psychotherapy research? Since the first randomized trials of psychotherapies in the 1970s, hundreds of trials have been conducted. Psychotherapies for depression have been examined most extensively, with about 500 randomized trials.7 These trials have shown that different types of psychotherapy are effective in the treatment of depression, including CBT, IPT, behavioral activation therapy, problem-solving therapy, nondirective counseling, and psychodynamic therapy.7,8 A large group of comparative outcome studies have shown that these therapies all seem to be equally effective or about equally effective.