Research Could Explain Why Adolescents are More Prone to Substance Abuse, Addiction
The researchers found that the stimulation in adolescent brains varied throughout the study and with a greater degree of disorganization, whereas the adult brains processed their rewards with a more consistent balance of stimulation and inhibition. This could help explain why adolescents are more vulnerable to drug addiction, rash decisions, and mental health problems.
Lead researcher Bita Moghaddam, a professor of neuroscience at Pitt’s School of Arts and Sciences, along with co-author David Sturman, a neuroscience doctoral student at Pitt’s, examined the extreme differences in the reactions to reward in neurons in the orbitofrontal cortex, a brain region that deals with the payoff and punishment of planning and making decisions.
Moghaddam said that the disorganized stimulation suggests that rewards are processed differently by the adolescent brain, which could intensify the effect of the reward on decision making and answer questions about why adolescents are more susceptible to substance abuse and why they have more extreme reactions to experiences, both pleasurable and upsetting.
Malfunctions in the orbitofrontal cortex have been seen in cases of schizophrenia and other mood disorders, Moghaddam said. This stimulated brain activity could worsen these conditions when an adolescent’s brain is developing.
Moghaddam said that the symptoms of mental disorders usually appear during adolescence, which is a period of vulnerability. Disorganized brain activity and excess stimulation could push the brain too far, triggering the onset of mental disorder symptoms.
This study is the first to examine and compare individual neuron activity in adult and adolescent brains while performing a task. In the study, the researchers gave adult and adolescent rats three holes to poke their noses through; when they chose the central hole, they received a sugar pellet.
When the adolescent rats received the pellet, their brains showed surges of stimulation that ranged from twice to four times that of the adults. As the adult rats received the pellets, the orbitofrontal cortex showed the normal increase of stimulation at consistent levels. The inhibitory impulses in the adolescents hardly changed from the low levels they experiences before receiving the reward.
Source: Science Daily, Teen Brains Over-Process Rewards, Suggesting Root of Risky Behavior, Mental Ills, January 26, 2011