Resilience and genes

The Question of Resilience

By EMILY BAZELON

Excerpts from New York Times Magazine article April 30, 2006

In recent years, biological science has proposed a new paradigm. The latest research shows that resilience can best be understood as an interplay between particular genes and environment — GxE, in the lingo of the field. Researchers are discovering that a particular variation of a gene can help promote resilience in the people who have it, acting as a buffer against the ruinous effects of adversity. In the absence of an adverse environment, however, the gene doesn't express itself in this way. It drops out of the psychological picture. "We now have well-replicated findings showing that genes play a major role in influencing people's responses to adverse environments," says Sir Michael Rutter, a leading British psychiatrist ...

Scientists have determined that 5-HTT is critical for the regulation of serotonin to the brain. Proper regulation of serotonin helps promote well-being and protects against depression in response to trauma or stress. In humans, each 5-HTT gene has two alleles, and each allele occurs in either a short or a long version. Scientists are still figuring out how the short allele affects serotonin delivery, but it seems that people with at least one short 5-HTT allele are more prone to depression. And since depression is associated with unemployment, struggling relationships, poor health and substance abuse, the short allele could contribute to a life going awry....

In their 2003 study, Caspi and Moffitt looked at 847 New Zealand adults and found a link between having at least one short 5-HTT allele and elevated rates of depression for people who had been mistreated as children or experienced several "life stresses" — defined as major setbacks with jobs, housing, relationships, health and money. Having two short alleles made it highly likely that people who had been mistreated or exposed to unhinging stress would suffer depression. One short allele posed a moderate risk of depression in these circumstances. Two long alleles, on the other hand, gave their carriers a good chance of bouncing back under negative circumstances. ....

It seems that only under dire circumstances — abuse, the strife of war, chronic stress — is the gene triggered. Eventually scientists hope to understand more about other genes that most likely play a role like 5-HTT's....

In an ongoing study, Suomi has found that motherless, peer-raised monkeys who have a copy of the short 5-HTT allele are more likely to experience fear, panic and aggression (accompanied by low levels of serotonin acid in spinal fluid) when a strange monkey in a cage is placed next to them. Motherless, peer-raised monkeys with two long alleles, on the other hand, are more likely to take the presence of the stranger in stride, as mother-raised monkeys do....

Having "good support" isn't just a question of good luck. Researchers have found that children who are resilient are skillful at creating beneficial relationships with adults, and those relationships in turn contribute to the children's resilience....

Eventually, a designer drug might succeed in mimicking precisely what the long-allele variation of 5-HTT does to foster resilience. "A magic drug down the line — yes, that's the whole point of understanding the neurological mechanisms," Joan Kaufman says....