What’s the Difference Between Tolerance, Dependence, and Addiction?

It can be hard to understand human nature, especially when that nature leads us to make harmful decisions. The questions seem endless. Why does someone need more and more of the same thing? Why doesn’t the small dose an addict started with have the same effect as it did in the beginning? How can this ever-growing need be stopped?

Before healing can be begin, we first need to understand the difference between tolerance, dependence, and addiction.


When using an addictive substance, the pleasure received will not remain the same. Eventually, a small dose will fail to have the same effect as it once did and that is why addicts tend to need more and more of something. They want the same feelings of pleasure they received when they first started using the drug. To do that, you need to increase the dose.

To define it, Merck Manual said tolerance “is a person’s diminished response to a drug, which occurs when the drug is used repeatedly and the body adapts to the continued presence of the drug.”

Medical News Today said, “After a while, the user of the potentially addictive substance does not get the same pleasure and has to increase the dose – his/her body’s tolerance to it increases. Eventually, the user no longer experiences pleasure from the substance and takes it simply to prevent withdrawal symptoms – taking the substance just makes them feel normal.”

The National Institute on Drugs or NIH said, “The development of tolerance is not addiction, although many drugs that produce tolerance also have addictive potential.”

Tolerance and addiction are not alone though. There is also drug dependence.

Drug Dependence.

The NIH said that drug dependence and addiction can go hand in hand, but are slightly different.

Drug dependence is when one has a “strong desire to experience the effects of the drug.” This can be physical or psychological.


Addiction though, is what seems to tip the scale. A drug user, as much as they may want to be clean, cannot stop taking the drug. That is addiction.

NIH summarized it simply:

“Addiction is a brain disease.

  • Drugs change how the brain works.
  • These brain changes can last for a long time.
  • They can cause problems like mood swings, memory loss, even trouble thinking and making decisions.”

Tolerance, drug dependence, and addiction can seem to be very similar. Understanding their subtle differences can help the addicted and their loved ones find the best path to freedom and healing. If you or a loved one needs help facing their addiction, learn more about Steps Recovery Center, a drug rehab in Utah dedicated to treatments and help that work. Addiction is painful, but we can help one become strong again.

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