The human brain is the most complex organ in our body, and is characterized by a unique ability called neuroplasticity. Neuroplasticity refers to our brain’s ability to change and adapt in its structural and functional levels in response to experience. Neuroplasticity makes it possible for us to learn new languages, solve complex mathematical problems, acquire technical skills, and perform challenging athletic skills, which are all positive and advantageous for us. However, neuroplasticity is not beneficial if we develop non-advantageous learned behaviors. One example of non-advantageous learning is habitual drug misuse that can lead to addiction.
Our brain learns to respond to drugs of abuse
Our first decision to use a drug may be triggered by curiosity, circumstances, personality, and stressful life events. This first drug exposure increases the release of a molecule (neurotransmitter) called dopamine, which conveys the feeling of reward. The increased changes in dopamine levels in the brain reward system can lead to further neuroplasticity following repeated exposure to drugs of abuse; these neuroplasticity changes are also fundamental characteristics of learning. Experience-dependent learning, including repeated drug use, might increase or decrease the transmission of signals between neurons. Neuroplasticity in the brain’s reward system following repeated drug use leads to more habitual and (in vulnerable people) more compulsive drug use, where people ignore the negative consequences. Thus, repeated exposure to drugs of abuse creates experience-dependent learning and related brain changes, which can lead to maladaptive patterns of drug use.
Views on addiction: Learning and disease
A recent learning model proposed by Dr. Marc Lewis in New England Journal of Medicine highlights the evidence of brain changes in drug addiction, and explains those changes as normal, habitual learning without referring to pathology or disease. This learning model accepts that drug addiction is disadvantageous, but believes it is a natural and context-sensitive response to challenging environmental circumstances. Dr. Nora Volkow, director of the National Institute on Drug Abuse (NIDA), and many addiction researchers and clinicians, view addiction as a brain disease triggered by many genetic, environmental, and social factors. NIDA uses the term “addiction” to describe the most severe and chronic form of substance use disorder that is characterized by changes in the brain’s reward, stress, and self-control systems. Importantly, both learning and brain disease models accept that addiction is treatable, as our brain is plastic.
We can adapt to new learned behaviors
Our brain’s plastic nature suggests that we can change our behaviors throughout our lives by learning new skills and habits. Learning models support that overcoming addiction can be facilitated by adopting new cognitive modifications. Learning models suggest pursing counseling or psychotherapy, including approaches such as cognitive behavioral therapy (CBT),