A team of U.S. researchers reported on Wednesday that according to a new study conducted on worms, an antidepressant called mianserin might lengthen life. The drug appears to have extended by about 30 percent the life span of the nematode Caenorhabditis elegans, and although there is a major difference between worms and humans, the scientists hope to find out whether the antidepressant has the same effect on people.

But even if mianserin helped us live longer, we would have to think twice whether to use it or not, as the life-extending benefits come at a cost. According to Michael Petrascheck of Fred Hutchinson Cancer Research Center in Seattle, "Weight gain and increased appetite seems to be one of the side effects. It is one of the reasons these are not such popular antidepressants.”

The team of researchers led by Nobel Prize recipient Linda Buck did a random search through 88,000 different drug compounds before finding four drugs that extended life span by 20 to 30 percent; mianserin, which makes part from a class of drugs known as tetracyclic antidepressants, had the strongest effect.

This antidepressant seemed to block brain cell signaling by two neurotransmitters (or message-carrying chemicals): serotonin, which is related to mood and appetite, and octopamine, which complements serotonin and signals starvation. However, Linda Buck said that it was possible that mianserin tipped the balance in the direction of octopamine, thus tricking the brain into thinking it has been starved.

The scientists that were involved in this study warned that these were incipient findings and asked people not to rush to take the drugs in the hope of living longer. "It is a stretch from a worm to a human being," as Michael Petrascheck said.