Morphine can lead to tolerance and dependence, even when taken as prescribed. With long-term morphine use, the body develops opioid tolerance, meaning higher doses are needed to achieve the same pain-relieving effects. This escalation can result in prescription opioid dependence, where you experience withdrawal symptoms if you stop using the drug.
However, it’s important to distinguish between dependence and morphine addiction. Dependence refers to the body’s physiological adaptation to the drug, causing withdrawal symptoms if you stop taking morphine. It’s why your doctor tells you not to stop taking your prescription suddenly. Addiction is characterized by compulsive drug-seeking behavior despite negative consequences. While dependence can occur without addiction, the two often coexist.
Research from the National Institute on Drug Abuse (NIDA) shows that long-term morphine use alters brain function by disrupting the brain’s natural reward system. Repeated exposure to opioids floods the brain with dopamine, which, over time, dulls the brain’s ability to release dopamine naturally.
This rewiring affects motivation, impulse control and stress response, making it harder to feel pleasure or regulate emotions without the drug. These changes can last long after you stop using morphine, increasing relapse risk and reinforcing both physical and psychological dependence.