A common issue in the treatment of patients with depression is compliance with antidepressant drug regimens. Dropout rates from clinical trials are as much as 33 percent, regardless of the drug class being evaluated. Still, the vast majority of clinical trials for depression use an assessment of depression as the only outcome measure and do not provide any information about adherence to medication regimens. Psychologic treatment is used in addition to medications to improve outcomes in patients with depression. The combination of psychologic treatment with medication may have some added benefit in improving adherence to pharmacotherapy. Pampallona and colleagues performed a systematic review of randomized clinical trials that evaluated pharmacotherapy versus combined treatment with pharmacotherapy and psychotherapy in patients with depression.

The authors performed a literature search in multiple databases to find randomized clinical trials that assessed the use of pharmacotherapy in one treatment arm versus combined pharmacotherapy and psychotherapy in the treatment of patients with depression. They also reviewed clinical guidelines and reference lists of published articles to determine if any additional studies should be included in the review. Data extracted from the studies were diagnosis, gender, mean age of the study sample, antidepressant drug administered, duration of the study, type of combined treatment, the number of patients with full response, the number with partial or no response, and the number that dropped out of the study. The antidepressant dosage was converted to milligram equivalents of imipramine hydrochloride using a published conversion chart. The quality of the methodology of each study also was evaluated.

There were 16 trials that met the inclusion criteria. The total number of patients enrolled in antidepressant therapy alone was 932, and 910 patients were enrolled in the combination portion of the studies. Patients in the combined treatment arms improved significantly compared with those receiving pharmacotherapy alone. No significant differences were noted in dropout and non-responder rates between the two treatment arms. When assessing dropouts and non-responders in trials that lasted more than 12 weeks, there was a significant benefit with combined therapy. Assessing the quality of the study had no impact on these variables.

The authors conclude that the combination of pharmacotherapy and psychotherapy provides a better improvement rate in patients with depression than pharmacotherapy alone. They add that in longer studies, psychotherapy helped keep patients in treatment. They note that further studies should be performed to determine if this improvement with combined therapy can be matched with pharmacotherapy combined with a compliance-enhancement program.