Some science stories are echoed all over the media and quickly. Here are a couple of common headings for a recent story: “Psychopaths’ Brains Wired to Seek Rewards, No Matter What the Cost” and “Psychopaths Produce Excessive Dopamine.” The original story is in Nature Neuroscience under the website title Psychopathic traits correlate with hyperreactive dopamine signaling. The paper itself is titled Mesolimbic dopamine reward system hypersensitivity in individuals with psychopathic traits.

I bring up this chain of titles not because re-titling is at all novel but because I think many people, including writers and editors, have a strong reaction to the word psychopath. Why? How many movies, thriller novels, video games, and TV shows have “psycho” or “psychopath” in their titles or as the main story? People exposed to modern entertainment media are conditioned to be interested (titillated) by the psychopathic. Not that the paper from a study at Vanderbilt University (Tennessee, USA) isn’t worthy of wide attention, but one has to suspect that its currency is in the word psychopath, not so much in the science.

The research began with a ‘twist’ in approach: Most research into psychopathology starts with what these individuals lack – fear, empathy, moral sense. Instead, this research wanted to know about qualities psychopaths have too much of – impulsiveness, high attraction to rewards, and almost insatiable risk taking. These are commonly identified as ‘psychopathic traits’ and the Vanderbilt scientists wanted to know if there was any neurological manifestation associated with the traits. They suspected it might be dopamine, a neurotransmitter with multiple functions in the brain, including involvement in the ‘reward centers’ of the brain.

To examine the relationship between dopamine and psychopathology, PET scans (positron emission tomography) of the brain were taken to measure dopamine release, together with an fMRI (functional magnetic imaging) to probe the neurological reward system in the brain. Study participants were screened and evaluated on the basis of a personality test; they ranged from ‘normal’ people with some pathological tendencies (manipulativeness, egocentricity, aggression, and risk taking) to violent criminals.

First the volunteers were given a dose of amphetamine (speed) and their brains were scanned to view dopamine release. It was found that people with the highest levels of psychopathic traits had almost four times the amount of dopamine released in response to the amphetamine. Second, the subjects were told that they would be given money as a reward for completing a task. Their brains were scanned with fMRI while they did the task. Those people with elevated psychopathic traits showed much higher activity in the dopamine reward area of the brain (the nucleus accumbens) while anticipating the reward. As a possible interpretation, Joshua Buckholtz, the lead author of the study, said:

“It may be that because of these exaggerated dopamine responses, once they focus on the chance to get a reward, psychopaths are unable to alter their attention until they get what they’re after.” Added [David] Zald, “It’s not just that they don’t appreciate the potential threat, but that the anticipation or motivation for reward overwhelms those concerns.”

[Source: EurekAlert]

In short, I suppose, it sounds like psychopathology is a kind of dopamine addiction. Does this suggest that manipulation of dopamine levels might be a way of controlling pathological behavior?

The study is based on scanning techniques, which provide locations of activity in the brain. It does not interpret in detail how dopamine in some locations is correlated to pathology. It does not deal with the biochemistry involved or with the detail of neuronal structure. It is not answering questions about the genetic background or development of psychopathology. The authors of the study make no claims in any of these areas. They find – in a quite simple way – that dopamine reward is associated with the satisfaction of desires that are pathological.

I wonder in how many media outlets the take-away of this story is that dopamine is a key to treating psychopathology? Or is there nothing here except the nice headline with PSYCHOPATH in it?  {via SciTech Story}