How do drugs affect the brain?
Drugs alter the ways in which neurons communicate with one another and process information through altering the function of neurotransmitters, which is how substance abuse affects the brain.
Because their chemical structure is similar to that of a naturally occurring neurotransmitter in the body, substances like marijuana and heroin are able to stimulate neurons.
As a result, these drugs are able to bind to the neurons and begin working. Although these medications are structurally similar to natural neurotransmitters, their use results in the aberrant transmission of messages across the brain’s neural network. Drugs like amphetamine and cocaine can disrupt the normal recycling of neurotransmitters by interfering with transporters, leading to excessive release of these chemicals from neurons. Again, this may either amplify or disturb the typical interaction between neurons. Changes in regions of the brain critical for maintaining life can contribute to the obsessive drug seeking and use characteristic of addiction.