The Neurobiology of Impulsivity: The Origin of Loss of Control

Have you ever spoken or reacted without thinking, and ended up hurting someone? There are few events that can trigger such negative consequences as losing control of our behavior. However, what happens in the brain in these situations?

Written and verified by the psychologist Valeria Sabater.

Last update: 19 October, 2022

Do you often have the feeling that there are two people living inside you? There’s the one who’s sensible, thoughtful, and calm. Then there’s the other who acts automatically and on impulse giving you no chance to stay in control. Impulsivity is an unpleasant enemy that leads you toward unregulated behaviors that you later regret.

Sometimes, you might find yourself raiding the fridge late at night driven by a rampant kind of anxiety that makes you eat anything and everything. At other times, your impulsive mind makes hasty decisions for you, causing you to make monumental mistakes. However, you’d love to be able to always adopt the calm and meditative approach, the one that reflects before acting.

As a matter of fact, we’re all dominated at some point by our other selves. They react spontaneously without taking into account the consequences of their actions. But why does it happen? For example, what happens in the brain of the highly impulsive child who’s so difficult to educate? How can we instill in them a more thoughtful and relaxed attitude?

The neurobiology of impulsivity

Impulsiveness is defined as unexpected, excessive, and unreasoned reactions that people adopt in any kind of situation. It’s an almost automatic behavior in response to a desire or a need. In effect, you allow yourself to be carried away by a latent emotion without taking into account the consequences of your actions.

Everyone, at some point or another, has experienced this type of situation. Especially in our early years. This is no accident. In fact, impulsive behavior is common in children and adolescents because their prefrontal cortex doesn’t finish maturing until they’re 24 years old. This brain region is responsible for exercising executive functions and regulating behavior.

It should also be noted that impulsivity is present in numerous psychological disorders. Addictions, anxiety, depression, bipolar disorder, obsessive-compulsive disorder, as well as impulse control disorder or antisocial disorder have the same characteristic. Although it’s clear that not all impulsive behavior reveals a mental problem, the question is… what happens in our brains when we act in this way?

We’re impulsive for different reasons

Impulsivity arises for different reasons. Knowing these triggers is essential in order to apply different intervention techniques. Let’s take a look at them.

• The impulsive personality. The education an individual received or the context in which they’ve been raised and educated favors an intolerant approach to frustration, one that responds automatically.
• Response impulsivity. This is another typology with a biological origin. In these cases, people are unable to modulate their responses, apply self-control, or behave rationally.
• Choice impulsivity. These people are unable to delay reinforcements and gratifications. Furthermore, they seek immediate enjoyment and might adopt addictive behaviors.

Altered dopaminergic and serotonergic systems

Research conducted by Yale University (USA) delved into the neurobiology of impulsivity. The study claimed that one of its triggers lies in the deregulation of the dopaminergic (DA) and serotonergic (5HT) systems.

This alteration in the release of dopamine and serotonin causes people to have problems regulating and controlling their behavior. The cerebral cortex loses operability and is subject to impulsive mechanisms.

The peptide of impulsivity

A peptide is a type of molecule formed by the union of several amino acids. It’s been discovered that the peptide, MCH, which also acts as a hormone concentrating melatonin, in turn, mediates impulsiveness.

In fact, a study published in the journal, Nature Communications, demonstrated that MCH activates or regulates impulsivity through lateral hypothalamic neurons. Understanding these neural substrates of the neurobiology of impulsivity facilitates the development of increasingly novel treatments to treat dysregulated or problem behaviors.

The genetic origin and why some children are born impulsive

It’d be really useful to be able to detect early those with a greater tendency toward impulsive behavior. It’d allow us to give educational guidelines from childhood with the objective of preventing the various problems associated with mental health.

As surprising as it may seem now, in a few years we’ll be able to carry out this process. McGill University has developed a technique with which to diagnose young children who are most at risk for impulsive behavior. Research is currently in the experimental phase, but it’s  been possible to detect the presence of several genes in the prefrontal cortex and the striatum that mediate this type of pattern.

Identifying this neurobiological signature would facilitate, for example, the development of specific programs to educate in impulse control, resistance to frustration, and correct emotional management. This would undoubtedly be essential for all of us to learn. It’d be especially beneficial in respect of those people who risk suffering any associated problems in the future.

To conclude, it should be noted that we now have a much better understanding of the mechanisms of the neurobiology of impulsivity. In fact, we can all work on it and improve this characteristic that leads to so much discomfort and regret. Indeed, impulsivity makes us live with versions of ourselves that we simply don’t like. Something that should be avoided at all costs.