Tag Archives: maturity

Why They Act So Crazy – Science and Teenage Brain Development

Recent research shows the adolescent brain does not fully mature until approximately age 25. During the maturation process, the brain strengthens some neurons and neural connections through repeated use, and eliminates others through lack of use. Substance abuse further impairs and delays development, as and strengthens maladaptive neural connections through repeated use.

Scared Teen

Professionals working with adolescents need to be aware of brain development, brain functions, and the interactions with environment, substance abuse and other issues. Appropriate expectations of the teen must be in place, but must also take into account that their capabilities are functionally different from those of an adult. Assist teens to learn their strengths and to compensate for their weaknesses, and to think through risky behaviors and to think independently.

Structures in the brain delayed during normal adolescence.

The Amygdala: Regulates emotional reactions.  Teenagers have a tendency to react explosively and to misread others’ emotions. The amygdala or “drama center” of the brain develops far faster than the rest of the teenage brain, leaving other brain structures unable to respond appropriate or to control the emotional outbursts.

Prefrontal Cortex: Regulates information processing, judgment and behavioral control. We see this adolescent brain immaturity in teens’ poor judgment and impulsivity, foreseeing consequences and setting goals and plans. This is one of the last areas of the brain to mature, and we can clearly see that teen behavior makes more sense in the context of an immature prefrontal cortex. This area also manages organization, problem solving, critical thinking and the ability to learn from experience.

Limbic System:  Holds the pleasure and emotion centers, modulates the libido, and contains circuits vital for memory and motivation.

Temporal Lobe:  Critical for understanding and processing language, as well as middle term and complex memories. The temporal lobe controls auditory and visual learning and emotional stability.

Adults with alcohol use disorders had a significantly smaller volume of the hippocampus, a brain structure primarily responsible for memory.

Teen Brains

Effects on Behavior and Mood

Combine a fully active and developed amygdala with an underdeveloped prefrontal cortex, many of the mood swings and behaviors blamed on “raging hormones” make sense. The prefrontal cortex acts as the “brake” on all thoughts and feelings people have. It is the last area of the brain to develop, not fully maturing until at least age 24.

Unfortunately, this particular developmental lag also puts the adolescent at risk for making poor decisions, such as abusing drugs. Introduction of many drugs and alcohol into the still-developing teenage brain may have long-lasting and profound consequences. Substances can disrupt brain function in critical areas related to memory, motivation, learning, judgment, and behavior control. Not surprisingly, teens who struggle with alcohol and drug abuse often have school and family problems, poor school performance, physical and mental health problems and involvement with the juvenile justice system.

What is Normal?

Sensation seeking, impulsive and risk taking behavior are quite normal until the brain development process is complete. A typical teen with a development will prefer activities with peers that are exciting, and novel activities that provide interesting input. They will have a tendency to be attentive to social interactions, as well as to have difficulty controlling emotions. They also will struggle with the ability to consider negative consequences of their actions. Scare tactics, such as the DARE program, are ineffective for this reason – teens are simply less able to process fear of punishment.


The underdeveloped adolescent brain leads teens be more influenced by peers than adults are, and more prone to “group think. They engage in risky behavior more often than adults, in part due to their sense of invincibility. They get more of a “rush from taking risks, and rarely think about the possibility of consequences. Still – developing impulse control skills affects teenage reckless behavior. They experience rapid and extreme mood changes connected with their troubles with self-control. Part of a teen developing their own identity is experimenting with different activities and adult rules. However, their judgment and impulse control may result in making poor choices.

Environment plays a crucial role in determining whether a teen’s immature judgment will lead to criminal behavior. Most delinquent youth do not continue to commit crimes as adults.  Substance abuse has a negative effect on these odds. The younger a teen is when they start using substances, the more likely they are to self-report addiction later in life. Increased hormonal production may lead to greater drug use, and the still-developing amygdala definitely increases the teen’s feelings of social disinhibition when intoxicated, compared to adults.

Adolescence is a period of significant brain maturation, and one incomplete until the mid-twenties. Teens are more likely to react impulsively or on instinct without thinking of consequences when they face stress or emotional decisions. Professionals who work with teens must understand the primary developmental differences between adults and adolescents. They need to encourage growth in teens thinking, and be open about risks involved with teen behavior choices.

 Adolescents should receive acknowledgment and reward for independent thinking, and be assisted with setting goals. Future oriented thinking is difficult for teens, and they will need assistance in this. Professionals should also help them recognize and utilize their unique strengths