Tuesday, June 2, 2009

Why Clinical Trials for Anti-Depressants Always Work Better than Real Life

Researchers at UT Southwestern Medical Center have published the truth behind all the successful clinical trials for antidepressant drugs. They looked into why these drugs always perform better in the clinic than they do in the real world after FDA approval. Researchers believe the reason medications do not work as well in real life as they do in clinical studies is because there is a very limited type of study participant who is selected for drug trials; this profile differs significantly from the makeup of the real world.

Our clinical care in the United States is based on samples of patients that are totally different from the patient population actually treated in primary care and mental health facilities. Dr. Madhukar Trivedi, professor of psychiatry at UT Southwestern is the senior author of this study published in the May issue of the American Journal of Psychiatry. “Antidepressants should not be seen as a panacea. The general belief is that they work well, but they are less effective in real-world practice.” Trivedi believes that more work is needed to get trials to accurately predict the success of drugs in real applications.

As part of the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study scientists found that only 22 percent of the 2,855 participants treated with a commonly prescribed antidepressant would have met the criteria for inclusion in a typical antidepressant efficacy trial. Those who did meet the trial criteria had shorter bouts of depression, quicker response to medication, less severe side effects and fewer adverse events compared with those people with depression who were excluded from such a trial.

To this writer, it doesn't seem fair that companies are allowed to "stack the deck" in this way when designing drug trials.

The six-year, $35 million STAR*D study is the largest investigation on the treatment of major depressive disorder and is considered a benchmark in the field of depression research. It initially included more than 4,000 people from outpatient treatment sites across the country. About 65 percent of STAR*D participants, however, had a medical co-morbidity such as diabetes that typically would have excluded them from participating in other clinical trials to test the efficacy of antidepressants.

“Evidence is growing that depression is like other chronic medical illnesses where it’s not just one small, short bout, but a longer battle. People with depression may be at higher risk for other illnesses including obesity or diabetes, yet people with these conditions are excluded from drug trials for depression,” Dr. Trivedi said.


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