Ten volunteers responded to the placebo much better than the rest. By the end of the experiment, their anxiety scores had halved, whereas the others' stayed the same. Brain scans also showed that activity in the amygdala, the brain's "fear" centre, had dropped by 3 per cent.
To see if there were genetic differences between responders and non-responders, Furmark screened them for a variant of the gene for tryptophan hydroxylase-2, which makes the brain chemical, serotonin.Previous studies suggested that people with two copies of a particular "G" variant are less anxious in standard "fear" tests. Sure enough 8 of the 10 responders had two copies, while none of the non-responders did.
Furmark believes the effect of the gene may extend to other conditions where the amygdala is involved, such as phobias, pain disorders and even depression.
Wonder if we can make strong-willed, mythic imagination-prone people with this.