https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=1&ContentID=3051
The rational part of a teen’s brain isn’t fully developed and won’t be until age 25 or so.
In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain’s rational part. This is the part of the brain that responds to situations with good judgment and an awareness of long-term consequences. Teens process information with the amygdala. This is the emotional part.
In teen’s brains, the connections between the emotional part of the brain and the decision-making center are still developing—and not necessarily at the same rate. That’s why when teens experience overwhelming emotional input, they can’t explain later what they were thinking. They weren’t thinking as much as they were feeling.
https://www.livescience.com/17033-gamer-brain-reward-system.html
Compared with the infrequent gamers, the frequent gamers had much larger ventral striatums, a reward center in the brain linked to emotional and motivational aspects of behavior. Problems with this area have been correlated to disorders such as schizophrenia, addiction and obsessive-compulsive behaviors.
The teenagers also played a gambling game while the researchers scanned their brain activity. The
frequent gamers were faster at making decisions during the game, and their brains showed more activity in the reward circuit when they lost.
"This indicates that losing money is somehow rewarding for frequent gamers," Kühn told LiveScience. "This could be the neural basis of a phenomenon called 'loss chasing,' which is known from pathological gambling. It describes the phenomenon that pathological gamblers keep on playing even when they lose a lot of money."
This larger brain region could mean that the
brain of a gamer releases more dopamine (a brain chemical that helps control the brain's reward and pleasure centers) when playing. This has also been seen when Parkinson's disease patients take dopamine, and they sometimes acquire gambling and other addictions as a result.
https://www.scientificamerican.com/article/how-the-brain-gets-addicted-to-gambling/
The APA based its decision on numerous recent studies in psychology, neuroscience and genetics demonstrating that gambling and drug addiction are far more similar than previously realized. Research in the past two decades has dramatically improved neuroscientists' working model of how the brain changes as an addiction develops. In the middle of our cranium, a series of circuits known as the reward system links various scattered brain regions involved in memory, movement, pleasure and motivation. When we engage in an activity that keeps us alive or helps us pass on our genes, neurons in the reward system squirt out a chemical messenger called dopamine, giving us a little wave of satisfaction and encouraging us to make a habit of enjoying hearty meals and romps in the sack. When stimulated by amphetamine, cocaine or other addictive drugs, the reward system disperses up to 10 times more dopamine than usual.
Continuous use of such drugs robs them of their power to induce euphoria. Addictive substances keep the brain so awash in dopamine that it eventually adapts by producing less of the molecule and becoming less responsive to its effects. As a consequence, addicts build up a tolerance to a drug, needing larger and larger amounts to get high. In severe addiction, people also go through withdrawal—they feel physically ill, cannot sleep and shake uncontrollably—if their brain is deprived of a dopamine-stimulating substance for too long. At the same time, neural pathways connecting the reward circuit to the prefrontal cortex weaken. Resting just above and behind the eyes, the prefrontal cortex helps people tame impulses. In other words, the more an addict uses a drug, the harder it becomes to stop.
