April 30, 2002 — Effexor seems to work better than the most popular type of antidepressant, say British researchers who pooled data from 32 clinical studies.

The finding doesn’t mean people taking other antidepressants should switch. It doesn’t even mean that Effexor is really better than other drugs — only very large head-to-head studies can show for sure whether one drug works better or is safer than another. Yet the study results may have an impact on which drug doctors try first.

As initial therapy for depression, most doctors tend to use newer drugs that target a specific brain chemical — serotonin — involved in depression. These drugs, called selective serotonin reuptake inhibitors or SSRIs, increase the amount of serotonin in the brain. SSRIs include Celexa, Paxil, Prozac, and Zoloft.

Effexor does this, too, but it isn’t quite as specific. It also increases the amount of another chemical — norepinephrine — in the brain. Because of this extra effect, many doctors fear adding extra, unwanted side effects to treatment. But the new study found Effexor to be just as well tolerated as SSRIs.

“[Effexor] should be considered a first-line therapy for patients in whom efficacy needs to be maximized and in those failing to respond to SSRIs,” study leader Ian Anderson, MD, says in a news release.

Anderson and co-workers at the University of Manchester, England, analyzed studies including 5,562 patients treated for depression with either Effexor or another antidepressant drug. Those who received Effexor were 43% more likely to have their depression go into remission than those taking SSRIs. Effexor patients also seemed to do better than those taking the older class of antidepressants called tricyclics, but the significance of this finding is less clear.

None of the studies compared Effexor to other non-SSRI, non-tricyclic antidepressants such as Remeron and Wellbutrin.

Will doctors suddenly switch? Psychiatrist Mark I. Levy, MD, is skeptical. Levy sees patients in private practice and teaches at the University of California, San Francisco. He tells WebMD that it’s hard to interpret clinical studies of antidepressant drugs because even placebos — sugar pills — work nearly a third of the time. More importantly, he says, treatment must be individualized for each patient with depression.

“If placebo gives a 30% effect, and they say Effexor gives a 43% better effect — what is that 43% response, really?” Levy says. “I am skeptical because I have seen different people respond to different drugs. I don’t know of any yardstick to use to tell who will respond to SSRIs and who will respond to drugs like Effexor.”

Anderson and colleagues note that most of the studies included in their analysis were funded by Wyeth-Ayerst, the drug company that makes Effexor. The Anderson study itself received funding from this company.