The Teen Brain Values Reward Over Risk, But It's Not Dopamine Acting

Jul 6, 2015

The teen brain values reward over risk. That’s been long-known. But a new study from University of Pittsburgh researchers says teen aren’t risk-takers because they’re seeking a surge of dopamine, a neurotransmitter that helps control the brains reward and pleasure centers.

According to new research, when faced with the prospect of a reward, their dopamine neurons are less activated than in adults.

“We have to rethink essentially how dopamine factors into adolescent reward processing," said lead researcher and Professor of Neurosurgery Bita Moghaddam. "We know that they go and work harder for it, but perhaps it's not because they go and get a bigger rush, perhaps its because they’re not getting a big enough rush.”

The research is published in this month’s Biological Psychiatry.

Previous research had been based on the adult brain. But adolescent brains are different. For one, they aren’t fully formed.

The study was conducted on rats and showed that adult rats get a small dopamine rush from anticipating a reward while adolescent rats don’t get the same level of dopamine-based satisfaction. In humans, this is reflected in teenagers needing to do risky things in order to get that dopamine rush.

Researchers had rats work toward getting sugar pellets. When they heard a tone, they knew that if they pressed a lever or worked they could get a sugar pellet.

Moghaddam said they conducted this study because they’re interested in how adolescents process events in the environment differently than adults.

“Adolescence is a critical age for vulnerability for disorders such as addiction and schizophrenia,” she said.

The study also provided some clues as to why adolescents seem prone to doing the same thing over and over again, even when the results aren’t the greatest.

Moghaddam says when adults learn there will be no reward, their dopamine cells stop responding. Adolescent dopamine cells retain memories of past rewards.

“The way we think about how the adolescent brain works is really not how it works. And we really need to focus on getting more data and putting research into understanding how the brain works and deal with adolescent related problems,” she said.