Opioids are highly addictive, in large part because they activate powerful reward centers in your brain called endorphins, your brain’s feel-good neurotransmitters. Endorphins muffle your perception of pain and boost feelings of pleasure, creating a temporary but powerful sense of well-being. When an opioid dose wears off, you may find yourself wanting those good feelings back even if you no longer “need” the medication for its prescribed use. This is how potential drug misuse, abuse, or addiction starts.

Anyone who takes opioids is at risk of misusing them, abusing them, or developing addiction. Many legally and appropriately prescribed prescription opioids are misused or diverted to others who then abuse them. Misusing and abusing opioids can lead to addiction. Doctors define drug addiction as an irresistible craving for a drug, out-of-control and compulsive use of the drug, and continued use of the drug despite repeated, harmful consequences. Opioids have a high potential and well-known history for causing addiction in some people, even when the medications are prescribed appropriately and taken as directed. Individuals who become addicted may prioritize getting and using these drugs over other activities in their lives, often negatively impacting their professional and personal relationships. It is unknown why some people are more likely to become addicted than others.Your personal history and the length of time you use opioids play a role, but we can’t predict who’s vulnerable to eventual dependence on and abuse of these drugs. 

Opioids change the chemistry of the brain and lead to drug tolerance, which means that over time the dose needs to be increased to achieve the same effect. Taking opioids over a long period of time produces dependence, such that when people stop taking the drug, they have physical and psychological symptoms of withdrawal (such as muscle cramping, diarrhea, and anxiety). Dependence is not the same thing as addiction; although everyone who takes opioids for an extended period will become dependent, only a small percentage also experience the compulsive, continuing need for the drug that characterizes addiction.