Saturday, January 14, 2012

Drinkers' utility

Folks measuring the social costs of alcohol are often pretty happy to assume that heavy drinkers get no utility from drinking; that lets them count private costs as socially relevant. For example, BERL wrote:


"We assume that it is irrational to drink alcohol to a harmful level and that harmful alcohol use has zero private benefit."

And now we see neurological evidence that the problem might rather be that heavy drinkers get too much enjoyment from alcohol:
Dr Jennifer Mitchell of the University of California San Francisco, who led the study, said: "This is something that we've speculated about for 30 years, based on animal studies, but haven't observed in humans until now.

"It provides the first direct evidence of how alcohol makes people feel good."

Researchers conducted positron emission tomography (PET) scans on the brains of 13 heavy drinkers and 12 non-drinkers immediately after they drank alcohol. Their findings, published in the Science Translational Medicine journal, showed that alcohol caused endorphins to be released in the nucleus accumbens and orbitofrontal cortex brain regions.

In all of the volunteers, larger quantities of endorphins released in the nucleus accumbens were linked to increased feelings of pleasure.

Increased levels of endorphins released in the orbitofrontal cortex were linked to a more pronounced feeling of intoxication in people who were heavy drinkers, but not in non drinkers, the study showed.

Dr Mitchell said: "This indicates that the brains of heavy or problem drinkers are changed in a way that makes them more likely to find alcohol pleasant, and may be a clue to how problem drinking develops in the first place.

"That greater feeling of reward might cause them to drink too much."
I'm happy to grant that heavy drinkers may experience costs in excess of benefits on the later units of consumption. But to assume away the existence of benefits runs contrary to common sense, and to the brain scan machines.

3 comments:

  1. "This indicates that the brains of heavy or problem drinkers are changed in a way that makes them more likely to find alcohol pleasant, and may be a clue to how problem drinking develops in the first place.

    "That greater feeling of reward might cause them to drink too much."

    The wording here is ambiguous. "(A)re changed" suggests that the differential endorphine production is a consequence of differences in alcohol consumption. The last sentece suggests that heavy drinkers were more likely to react to drinking with high endorphine production all along. The two aren't mutually exclusive (and both consistent with the results as reported in your link), but I would put the emphasis on the second aspect (and have).

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    Replies
    1. Either way, alcohol produces endorphins even among heavy drinkers. And endorphins is just another way of saying utils for the hedonometer.

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  2. But don't expect these findings to alter the behaviour of the social engineers/do-gooders!

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