Depression is characterized by sadness, anxiety, hopelessness, and fatigue so overwhelming that they interfere with a person’s ability to work, sleep, eat, or enjoy life. These symptoms can last weeks, months, even years.

Major depressive disorder is one of the three main types of depressive disorders (along with dysthymic disorder — long-term melancholy—and bipolar disorder ). In the United States, major depressive disorders are most commonly treated with antidepressant medications (ADMs). Physicians tend to favor selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac) and paroxetine (Paxil) because they produce fewer side effects than other antidepressants. Studies have shown that antidepressant medications effectively treat depression, including severe depression.

Major depression can also be treated with cognitive therapy, which helps patients change their negative thought patterns and learn effective coping techniques. Studies of cognitive therapy for major depressive disorder have had positive results. But to date, no placebo-controlled study containing large numbers of people with moderate to severe depression has compared the effectiveness of antidepressant medications with that of cognitive therapy.

Now, in a study published in the April 2005 Archives of General Psychiatry , researchers report that cognitive therapy can be as effective as antidepressant medications for the initial treatment of moderate to severe major depression. Importantly, however, the researchers note that the effectiveness of cognitive therapy varies substantially depending on the therapist’s level of experience.

About the Study

The researchers recruited 240 people, aged 18 to 70 years, who had been diagnosed with moderate to severe depression (measured by a score of 20 or higher on the HDRS, or Hamilton Depression Rating Scale).

The treatments, which took place at two test sites (the University of Pennsylvania and Vanderbilt University), were randomly assigned as follows:

120 patients received the antidepressant paroxetine (Paxil) for 16 weeks, with dose adjustment as needed.

60 patients received a pill placebo for eight weeks.

60 patients were assigned to 16 weeks of cognitive therapy, which was tapered down from twice-weekly sessions during the first four weeks to once-weekly sessions by the final four weeks.

During the first eight weeks, both patients and researchers were blind to who was receiving paroxetine and who was receiving a placebo pill; after that, both patients and researchers were aware of their treatment assignments.

The researchers evaluated the severity of the patients’ depression at eight weeks and then again at 16 weeks. They noted how many patients were responding to treatment (HDRS score of 12 or lower) and how many were in remission (HDRS score of 7 or lower).

The Findings

After eight weeks of treatment, 50% of the medication group, 43% of the cognitive therapy group, and 25% of the placebo group were responding to treatment. Both medication and cognitive therapy had a significant beneficial effect compared to placebo. However, the difference in effectiveness between medication and cognitive therapy was not statistically significant.

At 16 weeks, 58% of patients in both the medication and cognitive therapy groups were responding to treatment. Forty-six percent of the medication patients were deemed to be in remission at this time, compared to 40% of patients in the cognitive therapy group.

The researchers also compared outcomes separately for the two test sites at 16 weeks. They found that at the University of Pennsylvania, the difference in the response and remission rates between the medication and cognitive therapy groups was not significant. At Vanderbilt, however, medications were significantly more effective than cognitive therapy. According to the study authors, the therapists at the University of Pennsylvania were more experienced than those at Vanderbilt.

Although the researchers looked at the differences between outcomes at the two test sites, their analysis is limited by the fact that the study was not originally designed to consider the effect of the test sites on treatment efficacy.

How Does This Affect You?

Even though antidepressant medications are the most commonly used treatment for major depressive disorder in the United States, this study demonstrates that cognitive therapy can be just as effective over a comparable period of time.

However, this study also raises the issue therapist experience. In this study, all therapists were asked to follow standard guidelines for cognitive therapy. Yet only the cognitive therapy given by the more experienced therapists at the University of Pennsylvania produced results that were comparable to those of the antidepressant medications.

Although the influence of therapist experience on the success of treatment needs further study, it stands to reason that a skilled practitioner will produce better results. The Substance Abuse and Mental Health Services Administration (SAMHSA) recommends the following considerations when choosing a mental health therapist:

  • Ask your primary care physician for recommendations
  • Find out about the therapist’s experience, education, and number of years in practice
  • During your first visit, discuss the approach the therapist is planning to take and consider whether it feels right for you
  • Make sure the therapist has experience working with patients whose problems are similar to yours