American researchers are suggesting that antidepressant drugs may possibly lengthen a person’s lifespan.

The researchers from the Fred Hutchinson Cancer Research Center, in Seattle have come up with this possibility following research with nematode worms which are a very basic life form. In the study the tiny worms were exposed to as many as 88,000 chemicals drug compounds before four drugs were found that extended life span by 20 to 30 percent.

One of these drugs was Mianserin, which belongs to a class of drugs known as tetracyclic antidepressants, which proved to be the most effective in that it extended the lifespan of the worms by almost a third. The drug apparently mimics the effects on the body of the only known animal long-life regime - virtual starvation.

Experts say the findings might indicate genes in humans that could be targeted to increase lifespan and possibly to identify additional genes important in ageing.

Dr. Linda Buck of the research center says it remains unclear why, depriving the body of all but the minimum amount of calories needed to survive seems to enhance longevity but the Seattle team believe they may have found an easier way to achieve the same effect.

Nematode worms are ideal subjects for studies into lifespan, they are similar in many ways to humans as they have a central nervous system and sexual reproduction; they also only live for only a matter of weeks.