No one thinks that they will become an addict when they first experiment with drugs; however the brain has ulterior motives producing changes at a biological level that promote addictive behaviors. According to Leshner, director of the National Institute on Drug Abuse, repeated drug abuse can alter the biological chemistry of the brain, including disposition and memory, which adversely affects a person’s behaviors. Additionally, while social and environmental factors may have an influence on drug addiction, they are but a consequence of the chemical changes in the brain (Kreek, Nielsen, Butelman, & LaForge, 2005). Some of the ways in which drug addiction can change the structure and function of the brain include disruption of the neurochemical systems, genetics, and the dysfunction of the reward system. These factors help facilitate addiction through cravings, positive reinforcement, external cues, and predisposed tendencies. While there has been a debate over whether drug addiction is attributed to social or biological factors, research points to addiction being explained through biological factors that subsequently result in behavioral changes.
While ingesting drugs consciously affects the psychological state, unbeknownst to most they also have a physiological effect in the brain. For example, alcohol has significant damage on the frontal lobes in the brain, increasing the size of the ventricles, and creating irregular changes in neurotransmitters (Troupe, 2014). According to the Erickson (n.d.), drugs influence the brain by swapping out neurotransmitters for the drug and binding it to the receptor, by blocking the reuptake of neurotransmitters, and by interfering with neurochemical reactions. Furthermore, drugs like cocaine block the reuptake of neurotransmitters, such as dopamine, causing them to accumulate in the synaptic cleft (Koob & Moal, 2001). With that said, desensitization can occur when there is an overexcitement of neurotransmitters resulting in a decreased sensitivity on the receptors (Erickson, n.d.). The biological factors of these drugs on neurotransmitters can have long-lasting effects on an individual’s functioning, daily activities, and overall mentation. Drugs like MDMA, commonly known as ecstasy or Molly, have a profound effect on neurons that affect serotonin, creating oxidative and metabolic stress on the system (Troup, 2014). As serotonin is a neurotransmitter largely involved in the regulation of mood and positive emotions, the use of drugs such as this can have a drastic impact on the overall mental health of individuals who abuse drugs. Additionally, marijuana depends on cannabinoid receptors affecting the endocannabinoid system from normally functioning in the brain (Troupe, 2014). Consequently, being that these neurotransmitters regulate the brain as well as the body, disrupting their function can have dramatic effects on mood, sleep, appetite, emotions, as well as the nervous system, immune system, and behaviors. Therefore, drug abuse has a dual function of impacting current physical and mental health as well as influencing future health through the disruption of the body’s immune response system in fighting infection, disease, and other related physical issues.
Neurotransmitters are interconnected to a variety of biological pathways including the reward system that drives and reinforces pleasurable stimulus and experiences. According to Koob and Moal (2001), the ventral tegmental area of the brain, which is a part of the reward system, controls the release of the pleasure chemical dopamine. Also, while some drugs may trigger certain region of the brain, the ventral tegmental area and nucleus accumbens are associated with all drugs (National Institute on Drug Abuse.) Moreover, alcohol, marijuana, opiates, and cocaine hijack this reward system causing a rerouting in our brain to desperately seek out that state of euphoria that the body and