Some Parkinson disease patients taking drugs to boost their dopamine levels believe that it not only makes them looser physically, also sometimes morally. People with Parkinson disease have reduced dopamine levels in their brains which causes body tremors and, in the worst cases, immobility. Neuroscientists believe that dopamine is also the brain's own "feel good" drug. In most people dopamine activates the brain's reward circuits encouraging them to repeat behaviors that elicit the shot of neurotransmitter.
Now the Washington Post is reporting that the dopamine boosting drugs when taken by a very few Parkinson's patients so overload their pleasure circuits that formerly staid people become promiscuous and gambling addicts.
The article was interesting, but I was fascinated the following observation by the Post reporter:
The notion that brain chemicals play a powerful—but hidden—role in human behavior is at odds with American convictions about free will and choice. Kanuch and other [Parkinson's] patients said they spent years believing they were responsible for their actions, only to find that the impulse for self-destructive behaviors vanished once they stopped taking a drug.
Drugs playing a powerful role "at odds" with convictions about free will and choice? Perhaps, but Americans are quite happily gobbling up pills to fix their depressions, insomnia and attention deficits–all of which might once have been blamed on demons or lack of character. And whatever "free will" is, it operates through brain chemicals (unless you believe the Cartesian notion that the soul controls your body and brain by sending immaterial signals through the pineal gland).