You Never Have to Feel This Way Again
About Opioid Dependence
How tolerance can lead to dependence:
When a person uses opioids, the brain gradually gets used to the drug and becomes less sensitive to it. As a result, the person needs more of the drug to achieve the same level of pleasurable feelings. This is how tolerance develops. With longer use or higher doses, the brain adjusts to the increased levels of opioids, and then requires those increased levels to feel satisfied or "normal" to avoid withdrawal. This is how tolerance can lead to dependence.
Physical dependence is typically associated with tolerance and withdrawal. Psychological dependence involves continued drug use despite harm. Psychological dependence can reach the point where people have uncontrollable cravings for the drug—and are willing to take significant risks to obtain it, regardless of the negative consequences to themselves, their families, their jobs, or their community.