Impulsivity in Adolescents and Related Teen Mental Illnesses

It’s true that teenagers can be impulsive. It’s the way they are wired. Although some might say that their impulsivity is simply characteristic of being adolescents because, in a way, they’re still lingering in childhood as they make their way towards adulthood. However, the impulsivity of adolescents is in fact mostly due to how their brains are wired.


An impulse is an urge to act. In the mental health field, it is the tendency to respond quickly, without any sort of thinking about the future or consequences. Some individuals have learned to control their impulses, to feel them, but not give into them. For instance, you might see a dress in the window, ask about its cost, and then think otherwise about buying it. This is a way of controlling your impulses. Whereas, a teen might see the dress, imagine how she might look in it, especially at the party this weekend, and buy it regardless of the cost. Another example is the person who experiences an insult from his supervisor. Although he would like to follow the impulse to curse her, he doesn’t. He wants to be able to keep his job, which pays for his mortgage and the needs of his family. An adolescent might not take the time to think about the consequences in the least. In a quick second, a teen might retort with an insulting comeback and potentially lose his job.

Brain Function

The impulsivity of teenagers (and of some adults) is the function of the frontal lobe of the brain, which is the most evolved and distinctly human part of the brain. This part of the brain is still developing in adolescents, and it completes its growth during the ages of 23-26. The frontal cortex performs reasoning, planning, judgment, and impulse control, necessities for being an adult. This might explain a teen’s tendency to make poor decisions, such as in the examples above, and an inability to discern whether a situation is safe. Teens tend to experiment with risky behavior and don’t fully recognize the consequences of their choices.

Mental Disorders

Teens actually think differently than adults. Another part of the brain still developing in teens is the grey matter, which contains most of the brain’s neurons and is known as the thinking part of the brain. For adults, the brain’s grey matter development is complete. To make matters worse, certain drugs and the use of alcohol, which can teens can be prone to use in excess, can further cloud judgment and bring about impulsivity.

If a teen continues to be excessively impulsive at home or work, then a therapist or psychologist might consider the illnesses of conduct disorder, attention-deficit hyperactivity disorder (ADHD), or personality disorders. Impulsivity is a characteristic of conduct disorder, with a tendency to break the rules and violate the rights of others. There is little regard for the consequences of action. A characteristic of ADHD is the tendency for a teen to react to stimuli in his or her environment immediately. She might easily be distracted by noises, urges, thoughts, and outside triggers. Although impulsivity is considered to be a normal feature of adolescence because of their developing brains, if it continues in excess, it might be a sign of a developing personality disorder.

Teen Borderline Personality Disorder

Personality disorders that include impulsivity as a strong feature include anti-social personality disorder (which is a diagnosis that commonly follows conduct disorder) and teen borderline personality disorder. For those diagnosed with borderline personality disorder, there is often very low self-esteem and impulsive behavior. Similarly for those with bipolar disorder and who experience mania, impulsivity can increase during their manic episodes. And for those with post traumatic stress disorder, impulsivity can also be a symptom. Teens with PTSD might always be tense and on edge.

Teens are in fact more impulsive than children; however, because they typically have more independence, they can make poor decisions and be a danger to themselves or others. They are often at high risk for getting into car accidents, gunshot injuries, STI,   pregnancy, and unintentional doses, and suicide.


It’s true that teens can be more impulsive because of their developing brains. However, the excessive and prolonged presence of impulsivity might indicate a possible mental illness.


Hicks, J.W. (2005). 50 signs of mental illness: A user-friendly guide to psychiatric symptoms and what you should know about them. New Haven, CT: Yale University Press