Brain plasticity in drug addiction: Burden and benefit
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.