The American Society of Addiction Medicine has gone as far as categorizing addiction as a chronic brain disorder since it changes the way the brain works by rewiring its structure. As drugs and alcohol enter someone’s system, they activate the brain’s reward system and release the chemical dopamine which causes the person to experience a euphoric effect.
Some people will develop an addiction to opioids after being prescribed them for a medical procedure while others might develop an addiction after experimenting with friends. As time passes, the person may need larger doses of opioids to get high and then they will need the drug just to feel normal. Any non-medically assisted attempts to stop drug use may cause intense withdrawal symptoms and make them feel physically and mentally ill.