This chapter delves into the complex interplay among addiction, stress, and the reward pathways in the brain, emphasizing the ways in which various drugs affect these systems and exacerbate SUD. Drugs have physiological effects that can be both pleasurable and unpleasant. These effects change behavior through both positive and negative reinforcement. A person's genetic predisposition to addiction is mostly determined by factors such as biological sex, age of first usage, and dopamine receptor density. Drug use behaviors are also greatly influenced by environmental stressors, media exposure, and substance accessibility; nevertheless, protective variables including social support, participation in healthy activities, and preventative programs serve to reduce the dangers associated with drug use. The reinforcement of addictive behaviors is mostly dependent on the brain's reward circuits, which include the nucleus accumbens, ventral tegmental region, and prefrontal cortex, in addition to neurotransmitters such as dopamine, serotonin, and endorphins. Stress makes addiction worse by intensifying cravings and raising the possibility of relapsing. Examined are the impacts of several drug types, such as opioids, stimulants, depressants, and hallucinogens, emphasizing the long-term consequences on brain function and susceptibility to addiction. In order to create individualized interventions that target the environmental and neurological components of addiction and eventually improve treatment results, a thorough understanding of these elements is important.
Keywords: Addiction; Neurotransmitters; Reward pathways; Stress; Substance use disorder.
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