SSRI ads questioned

Claims in drug monographs and advertising that selective serotonin reuptake inhibitor (SSRI) antidepressants work by normalizing serotonin levels are not based on scientific evidence and should be prohibited, says a leading US psychiatrist.

„Biological psychiatrists have looked very closely for a serotonin imbalance or dysfunction in patients with depression or obsessive compulsive disorder and, to date, it has been elusive,” says Dr. Wayne Goodman, Chair of the US Food and Drug Administration (FDA) Psychopharmacologic Drugs Advisory Committee. Although an SSRI may work well in an individual, this „doesn't prove that there is an underlying imbalance, defect or dysfunction in the person's serotonin system,” he added.

Goodman was reacting to a recent article (December 2005, PLoS Medicine) about the growing body of medical literature that casts doubt on the „serotonin hypothesis.” Co-author Jonathan Leo, associate professor of anatomy at Lake Erie College of Osteopathic Medicine, says the FDA should prohibit SSRI manufacturers from making these claims.

GlaxoSmith-Kline (GSK), for example, claims (www.paxil.com) that paroxetine (Paxil) can „help restore the balance of serotonin — which helps reduce the symptoms of anxiety and depression.” GSK officials refused to comment.

In 2003, Ireland's drug regulator banned GSK from stating on its patient information leaflet that paroxetine „works by bringing serotonin levels back to normal.” Officials stated that „There is no scientific investigation to measure what are normal serotonin levels in the human brain receptors. As such, claiming that a particular medicinal product works by bringing serotonin levels back to normal is not accurate.”

The claims do not appear on Canadian product information, says Health Canada spokesperson Chris Williams. The Paxil monograph states it is „thought to work by increasing levels of serotonin in the brain.”

Goodman would not comment on whether the FDA should ban these claims. While he accepts that claiming SSRIs correct a serotonin imbalance goes „too far,” he says he has no problem if patients are told that SSRIs normalize some kind of chemical imbalance or disturbance. „I think that is reasonable shorthand for expressing that this is a chemically or brain-based problem and that the medications are normalizing function.”