What does the term "tolerance" refer to in substance use?

The term "tolerance" in the context of substance use refers to the body's diminished response to a drug after repeated use. This means that, over time, an individual may require a larger dose of the substance to achieve the same effect that was previously obtained with a smaller dose. This phenomenon occurs because the body adapts to the presence of the substance, leading to changes at the cellular or physiological level that reduce the drug's effectiveness.

For individuals who develop tolerance, they may find that the initial amount of a substance no longer produces the desired effects, prompting them to increase their intake. This is a critical concept in understanding substance use disorders, as it can lead to escalating use and increased risk of dependency.

This understanding of tolerance is fundamental in the field of addiction treatment, as it helps professionals recognize the physical adaptation that occurs in users and the implications this has for treatment plans and interventions.