Addiction, known clinically as substance use disorder, impacts major areas of the brain. Different areas of the brain are responsible for specific functions and responses. Importantly, these reactions are what keeps us alive. However, when these systems are “hijacked” by addictive substances, it can have harmful effects and lead to negative consequences. Of course, there are many parts of the brain that are involved in addiction but three major areas are listed below:
- Prefrontal Cortex: This is like the control center of the brain. This region is involved in “executive functions” which means the ability to make decisions, organize thoughts, manage time, set priorities and manage impulses. The prefrontal cortex is not fully developed until the age of 25, which helps us to understand why many young people impulsively drink, smoke, or experiment with drugs for the first time. Brain imaging studies in people with addiction show disruptions to the prefrontal cortex that align with habitual substance seeking and impulsive and compulsive drug use.
- Basal Ganglia: This region of the brain controls the rewarding or pleasurable effects of substance use. This is also the area of the brain that releases feelings of pleasure from eating food or having sex thereby motivating us to continue these behaviors for survival and is responsible for habit formation. Repeated activation of this region of the brain through alcohol or drug use creates “positive reinforcement” for taking the substances, which results in the brain forming an intense desire, or craving, for these substances.
- Extended Amygdala: This area of the brain is involved in anxiety, stress, and irritability that typically accompany substance withdrawal. The drive to eliminate these bad feelings creates a “negative reinforcement” that compels alcohol or drug use.