(cm) The well-known antidepressant Prozac, which can also cause outbursts of violence and suicides, increases bone mass. This was discovered in mice by American researchers collaborating with ETH Professor Ralph Müller of the Institute for Biomechanics (1) . Their paper was published on-line recently in the scientific journal Journal of Cellular Biochemistry (2) .

In their studies, the scientists treated mice for six weeks with Fluoxetine (the generic name for Prozac). Next, using microcomputed tomography, they observed an increase in volume in the trabecular bones and also in the total volume of the thighbone and vertebrae. With Fluoxetine, increased bone mass was formed even when an inflammation was artificially provoked in the mice. This occurred even though untreated inflammation leads to bone loss.

However, the effect of Fluoxetine disappeared when the ovaries were removed from the mice. The animals lost bone mass in the usual way after this kind of operation. This is evidence that the anabolic, i.e. the building up action of Fluoxetine requires the oestrogens produced by the ovaries.

The study suggests that Fluoxetine treatment in vivo under normal physiological conditions and inflammatory conditions leads to increased bone formation but cannot prevent bone loss when there is oestrogen deficiency. Ricardo Battaglino, the American Forsyth Institute scientist leading the study, thinks this research provides important information as to how destructive bone loss can be avoided and how bone mass can be increased in certain medical or dental conditions.