The feel-good gene

In Australia, anxiety is even more common than depression. In fact, about one in four of us suffer from it.
The general belief is that stress or circumstances cause it. But, this might not necessarily be the case.
Richard Friedman, a professor of clinical psychiatry at Weill Cornell Medical College, says some of us have a feel-good gene that makes us less prone to anxiety and also to fear and addiction.

"For the first time, scientists have demonstrated that a genetic variation in the brain makes some people inherently less anxious, and more able to forget fearful and unpleasant experiences," Professor Friedman writes of the FAAH variant gene in the New York Times. "This lucky genetic mutation produces higher levels of anandamide - the so-called bliss molecule and our own natural marijuana - in our brains."

Suffering anxiety, is not a mark of character, but at least in part to do with the genetic lottery, he says.
"About 20 per cent of adult Americans have this mutation," Professor Friedman says of those who produce more anandamide, whose name is taken from the Sanskrit word for bliss.
"Those who do may also be less likely to become addicted to marijuana and, possibly, other drugs - presumably because they don't need the calming effects that marijuana provides."
It also changes the way they respond to fear.

A new study by Professor Friedman's colleagues from Weil Cornell has found that mice that were given the gene variant spent more time in the open (more anxious mice prefer the safety of the enclosed parts of the maze) and were better able to unlearn fear.

"Some of us, like those with this cannabinoid mutation, forget about previous dangers more easily and move around in the world with less anxiety," Professor Friedman says.

"This seems like a good deal for the species: We're protected by those who are anxious and vigilant and enriched by those who are more carefree and exploratory."

Understanding the feel-good gene is helpful therapeutically, Professor Friedman says, suggesting that it has "important implications" for personalised medicine and treatments; some people might need more sessions to eradicate a fear for instance, simply because of their genes.

That said, he points out that "environment plays a critical role and can sometimes even trump genetics".

He notes one study where primates who were less genetically prone to addiction were exposed to cocaine for an extended period of time, their receptors changed and they began to seek out the drug.
"Strikingly, the effect was reversible: With abstinence, 60 per cent of the primates' D2 receptor levels normalised," Professor Friedman says. "The clear implication is that probably anyone - regardless of genetic risk - can become addicted or abstinent in the right environment."

For those who have less "natural marijuana" in their brains, Professor Friedman advises against using the plant version to treat anxiety.

"The problem is that cannabis swamps and overpowers the brain's cannabinoid system, and there is evidence that chronic use may not just relieve anxiety, but interfere with learning and memory. What we really need is a drug that can boost anandamide - our bliss molecule - for those who are genetically disadvantaged. Stay tuned."