How the frontal cortex responds to opiate addiction

Participants were asked to complete a test of self-control in which they had to overcome an automatic response in favour of a more controlled alternative response, requiring them to control their impulsive tendencies.

The researchers found two important differences between the opiate-using group and the group who had never used heroin.

The opiate-using group needed to activate more of their brain by placing greater physiological demand on it to avoid making an error on a test of self-control. Brain cells in the frontal region of the brains of the heroin users also were revealed to be less healthy than the non-opiate-using group.

“What people don't tend to understand about long term drug users is that this is not a matter of choice. They have a reduced level of biological resources and find it hard to stop,” Dr Yucel said.

That's an interesting nuance; it seems to me like most people understand that addiction by its nature robs people of some measure of choice, even if they don't understand the full physiological picture of how that happens. But this type of research helps clarify that picture, and potentially offers insight toward new treatment methodologies.