"Medication is often an appropriate treatment, but drugs have drawbacks, such as side effects or a diminished efficacy over time," DeRubeis said. "Patients with depression are often overwhelmed by other factors in their life that pills simply cannot solve. In many cases, cognitive therapy succeeds because it teaches the skills that help people cope."
The researchers also noted slight differences in the response to treatment between the two testing locations, with cognitive therapy performing better at Penn and medications performing better at Vanderbilt. Researchers surmise that the medication worked so well at the Vanderbilt clinic because more of the patients there were markedly anxious, in addition to being depressed, and the medications used in the research have anti-anxiety properties.
The researchers further believe that cognitive therapy patients might have done better at Penn due to the experience level of the therapists involved. Just as the experience of therapists may be important in cognitive therapy, so, too, can the expertise of prescribing physicians play a role in the success of antidepressant medication treatment. Studies have shown that antidepressant medication dosages are still largely a matter of physicians' discretion.
"Clearly, cognitive therapy is not for everyone, and its success could depend on variables such as the expertise of the therapist and the patient's willingness or ability to take the therapy to heart," DeRubeis said. "The key to establishing any form of treatment is rating its effectiveness in comparison to treatments currently in use, and this study has shown cognitive therapy to be a viable alternative."