Even the gene responsible for depression has a silver lining, according to a new study by a team of researchers at the University of Melbourne, Australia. According to the study, the gene which makes people depressed following bad events in life, also results in happiness in other people who do not experience bad things of that sought.

The fact that not all people, who experience physical or sexual abuse as a child, develop long-term depression as an adult triggered the researchers to find the reason behind this behavior. The study findings seem to have challenged the traditional belief that the gene responsible for higher risk of depression makes an individual more vulnerable to it.

"Our results suggest some people have a genetic makeup that makes them more susceptible to negative environments, but if put in a supportive environment, these same people are likely to thrive," said researcher and psychiatrist Chad Bousman, in a statement.

During the study, the researchers focused on a gene called SERT, which is responsible for carrying the serotonin, or the mood-regulating chemical in the human body. There are three types of SERT genes -- long-long (l/l), the short-long (s/l) or the short-short (s/s) -- and each individual has only one type of SERT gene.

The researchers recorded the depressive symptoms of 333 middle-aged subjects. The symptoms were recorded each year for over a period of five years.

The team found that the 23 percent of the population with s/s genotype, who have had a sexual or physical abuse experience as a child, went on to develop depressive symptoms during their middle age. At the same time, subjects with same genotype and no history of abuse were found to be happier than the rest of the population.

The researchers said that the effect of the SERT gene on depression has never been studied before over a long period of time. According to Bousman, the findings of the team suggest that depressive symptoms are more affected by the life experiences of an individual.