Referred to by some scientists as the 'differential susceptibility hypothesis' or journalist David Dobbs as 'The Orchid Hypothesis', these findings shouldn't be understated. They are revolutionary, and suggest a serious rethinking of the role of genes in the manifestation of our psychological traits and mental 'illness'. Instead of all of our genes coding for particular psychological traits, it appears we have a variety of genetic mutations that are associated with sensitivity to the environment-- for better and worse.
Only a few genetic mutations have been discovered so far that demonstrate differential susceptibility effects. Most of the genes that have been discovered contribute to the production of the neurotransmitters dopamine and serotonin. Both of these biological systems contribute heavily to many aspects of humanity, including our cognitive exploration, engagement with the world, positive emotions, anxiety, depression, and mood fluctuations. So far, the evidence suggests (but is still tentative) that certain genetic variants under harsh and abusive conditions are associated with anxiety and depression, but that the very same genetic variants are associated with the lowest levels of anxiety, depression, and fear under supportive, nurturing conditions."
Article in its entirety: http://www.alternet.org/personal-health/new-sensitivity-gene-discovered?page=0%2C0