A team of Israeli scientists have experimented on rats to see how they cope with stress, and hope the study would contribute to understanding the cause of human depression and suicide.

Results of the study suggest that while exposure to stress in childhood increases the risk of depression, as one might expect, exposure to stress in adolescence may actually provide protection against depression and suicidal behaviour later in life.

"This is the case even for adolescents who were genetically predisposed to suicide," said the lead researcher, professor Gil Zalsman, deputy director and chief of the child psychiatry division of the Geha Mental Health Centre and associate professor in psychiatry at Tel Aviv University's Sackler School of Medicine.

The study also revealed the differences in the responses to stress between rats with a genetic predisposition to depression, meaning they have hormonal and behavioural abnormalities that emulate those found in depressed humans, and rats without a "depression gene". The research tested rats of the Wistar-Kyoto strain, which are genetically predisposed to depression & Wistar rats, exposing them to different types of stress.