uconn | “Often, depressed people say they don’t want to go out with their
friends,” says Salamone. But it’s not that they don’t experience
pleasure, he says – if their friends were around, many depressed people
could have fun.
“Low levels of dopamine make people and other animals less likely to
work for things, so it has more to do with motivation and cost/benefit
analyses than pleasure itself,” he explains.
In essence, says Salamone, this is how amphetamines work, which
increase dopamine levels and help people motivate to focus on tasks at
hand.
“When you give people amphetamines, you see them putting more effort into things,” he says.
The big implications of this change in understanding come at the
level of overlapping motivational symptoms of depression with those seen
in other disorders such as schizophrenia, multiple sclerosis, and
Parkinson’s disease. Symptoms of fatigue may be related to low levels of
dopamine or changes in other parts of the same brain circuitry.
On the one hand, this lack of perceived energy is maladaptive,
because it reduces the tendency to interact with the environment. But,
Salamone says, it could also reflect the body’s attempt to save energy
in a crisis.
He points out that new ideas in science are traditionally met with
criticism. But after all the mounting evidence, he says he’s no longer
regarded as “a crazy rebel,” but simply someone who thought differently.
“Science is not a collection of facts. It’s a process,” he says.
“First we thought dopamine was involved only in movement. Then that
faded and we thought it was pleasure. Now we’ve gone beyond that data on
pleasure.”
Although he has thought about writing a popular-press book, he’s not
sure he really wants to go to the public and “debunk” the dopamine
hypothesis of pleasure and reward. But if he ever does, one thing is for
sure.
“I can sum up all this work with one phrase, which would make a great
book title,” he says. “Dopamine: it’s not about pleasure anymore.” Fist tap Arnach.
