April 2009

A new report due to be published in the May issue of the American Journal of Psychiatry shows that antidepressants aren’t all they’re cracked up to be.

But, faithful readers, you already knew that. Right?

The report is part of the National Institute of Mental Health-funded Sequenced Treatment Alternatives to Relieve Depression (STAR*D) project – the largest study of the treatment of depression conducted in the United States. It showed that findings from clinical studies used to gain FDA approval of antidepressants are not applicable to most patients with depression.

Researchers at the University of Pittsburgh Graduate School of Public Health compared symptoms and outcomes in depressed patients who met phase III study inclusion criteria to those who did not. Phase III studies for antidepressants determine the effectiveness of the drug in comparison to a placebo.

The inclusion criteria for these studies aren’t standardized or subject to any federal guidelines. Typically this means that patients with milder forms of depression, chronic depression, or other psychiatric or medical conditions in addition to short-term depression are excluded from studies.

In other words, the majority of “real world” patients with depression who end up taking antidepressants are excluded from clinical studies. It should be obvious why this is a problem. In a normal, clinical setting many patients with depression do also have other illnesses, such as diabetes, chronic fatigue syndrome or irritable bowel syndrome (IBS). It’s not unusual for them to have anxiety and insomnia, as well. In fact, it wouldn’t be presumptuous to expect that a depressed person might be suffering from a number of conditions that are either contributing to or caused by their illness.

Yet the only people that “qualify” for the clinical trials which determine whether antidepressants get approved by the FDA are those with short-term depression, no history of depression, no other psychiatric conditions such as anxiety, and no physical illnesses like heart disease or diabetes. This is the only subgroup of the general population for which we have any data on the efficacy of antidepressants.

By the same token, this means is that we have almost no clinical data on how antidepressants work for the “real world” patients who are most likely to be taking them. Indeed, after assessing 2,855 patients treated with citalopram (Celexa), the study authors found that fewer than one in four, or 22.2%, of the patients met the usual criteria for inclusion in phase III clinical trials.

According to study lead author, Stephen Wisniewski, Ph.D., professor of epidemiology and co-director of the Epidemiology Data Center, University of Pittsburgh Graduate School of Public Health, “This raises major concerns about whether results from traditional phase III studies can be generalized to most people with depression, who also often suffer from anxiety, substance abuse and other medical and psychiatric problems.”

When Wisniewski and his colleagues looked at the efficacy of antidepressants in those who did not meet phase III inclusion criteria – meaning the majority of people who take the drugs in real life – they found that their outcomes were much worse than those who did qualify for the trials. The depression remission rate in the patients who met the criteria was 34.4 percent, compared to only 24.7 percent in the ineligible group.

So, here’s the bottom line: antidepressants are nowhere near as effective as research suggests.

And that is really bad news for the drug companies, because research already suggests that antidepressants aren’t very effective at all. In fact, as I explained in a previous article, antidepressants are no more effective than placebo for most people. If antidepressants are no more effective than placebo in the patients that do meet phase III criteria, and we know that antidepressants are less effective for patients who don’t meet phase III criteria (the vast majority of “real world” depression patients), then couldn’t we assume that antidepressants are less effective than placebo for most patients?

Yes, we could.

For more information on this topic, check out this index of my articles (as well as selected off-site resources) on depression and antidepressants.