What is Alcohol Tolerance?

By Eric Dean JD, MBA, MA, MA, LPC, CADC

The first time John drank alcohol he felt the effects after 2 drinks. The 300th time John drank it took 12 drinks to achieve similar effects. After many years of heavy drinking John has built up a tolerance to alcohol. According to the National Institute on Alcohol Abuse and Alcoholism (NIAA) alcohol tolerance generally means “…that after continued drinking, consumption of a constant amount of alcohol produces a lesser effect or increasing amounts of alcohol are necessary to produce the same effect.” In this post, I will describe 4 types of alcohol tolerance and the associated risks.

How Understanding Tolerance Can Help You Assess Your Drinking

1.       Pharmacokinetic Tolerance (Metabolism)

Our bodies are amazing machines that constantly change and adapt to our environment and behavior. When we drink, the liver processes most of the alcohol at a rate of about one drink per hour, so moderate drinking does not put too much strain on it. However, when we drink heavily, the liver becomes overworked and needs to adapt to process the alcohol efficiently and effectively. To do so the liver increases the number of enzymes available to metabolize the alcohol, thereby reducing the duration of alcohol’s effects. Consequently, the user needs to consume more alcohol to achieve the desired effect.

Risk: In response to tolerance, many users will continue to drink more and more. However, it is unlikely that they will ever feel the same pleasure they once did during the early stages of their drinking, yet they will still experience the negative side effects of increased consumption.

2.       Pharmacodynamic Tolerance

The brain also adapts to alcohol consumption patterns. Alcohol triggers the release of dopamine, a neurotransmitter involved with motivation, pleasure, and reward. Heavy drinking causes an unnatural increase in dopamine to which the body responds by producing less of it, reducing the number of dopamine receptors (downregulating), and/or desensitizing existing dopamine receptors. Consequently, the user needs to drink more to achieve the desired level of pleasure. If the user stops drinking, they may experience sadness or amotivation because the body is now producing less dopamine.

Risk: When tolerance develops, the body has reduced the natural production of neurotransmitters essential to well-being. Then, upon drinking cessation, the user has a deficit of these chemicals and consequently feels sad, tired, and irritable.

3.       Behavioral Tolerance

Heavy drinking may cause slurred speech, dizziness, and deficits in coordination and psychomotor skills. Over time, as one drinks more and more, they learn to adapt their behaviors to counteract alcohol-induced impairments. For example, the first time John drank too much he lost his balance and spoke incoherently. Many years later, after frequent and heavy binge drinking, John can consume three times as much and still maintain his balance and speak relatively comprehensibly.

Risk: Behavioral tolerance can make the user feel as if they are not as impaired as they really are, which leads to increased consumption and further negative consequences.

4.       Reverse Tolerance

Heavy drinkers report that at some point after years of binge drinking and increased tolerance, their tolerance reverses. There could be many reasons for this, but it may indicate that the liver is damaged to the point that it can no longer effectively process much alcohol at all. 

Risk: Reverse tolerance could indicate serious health problems such as liver damage.

Wrapping Up

Understanding your tolerance to alcohol will help you assess your drinking and make positive changes.

So let’s get started – call Symmetry Counseling today at 312-578-9990 or reach out online to get paired with a Chicago therapist.

Reference

“Alcohol and Tolerance – Alcohol Alert No. 28-1995.” National Institute on Alcohol Abuse and Alcoholism, U.S. Department of Health and Human Services, pubs.niaaa.nih.gov/publications/aa28.htm.