Tolerance, Dependence, and Addiction: What Common Substance Abuse Terms Mean
If you’re wondering whether addiction treatment is necessary for yourself or a loved one, it’s important to understand the difference between tolerance, dependence, and addiction.
Understanding Tolerance and Dependence
Tolerance occurs when a substance gradually loses its effectiveness over time. This means that a person needs a higher dosage to experience the same effects. Tolerance develops at different rates depending upon genetic factors and the type of substance being used.
Tolerance can be seen in three types: acute, chronic, and learned.
- Acute tolerance occurs over a short period of time, such as what is seen in new users of cocaine.
- Chronic tolerance develops over a longer period of time, such as what is seen with people who use prescription opioids.
- Learned tolerance occurs when someone develops ways to compensate for the effects of a substance, such as how frequent drinkers can alter their behavior so as not to appear intoxicated to the casual observer.
Dependence on a substance develops when the neurons in the brain adapt to repeated drug exposure and eventually only function normally in the presence of the drug. Dependence means that withdrawal symptoms will occur when the use of a substance is suddenly stopped. Withdrawal symptoms can be physical changes such as sweating, heart palpitations, or stomach upset. Mood changes such as fatigue, depression, anxiety, and nervousness may also occur.
Dependence on a substance can be tied to having a history of substance abuse, having co-occurring mental health conditions such as anxiety or depression, and being a teen or young adult when you began using the substance. However, dependence is still possible even in the absence of these risk factors.
Since withdrawal can be uncomfortable and sometimes physically dangerous, it’s most common for healthcare providers to slowly wean someone off the substance that caused the dependence. In an addiction treatment center, a medically supervised detox is used to manage withdrawal symptoms in the safest and most comfortable way.
Tolerance, Dependence, and Addiction
Addiction is characterized by feeling powerless to control the use of a substance even when you are experiencing harmful consequences. Someone with an addiction is also said to be suffering from a substance use disorder.
Tolerance and dependence can be warning signs of addiction, but they do not necessarily mean that someone is addicted to a substance. In the case of prescription medications, tolerance and dependence can occur even when the substance is used precisely as prescribed. For example:
- Tolerance to prescription opioids can occur if a patient suffers from chronic pain and is taking the medication for a long period of time.
- The use of anxiety medications can create withdrawal symptoms if the patient has been taking the medication for a long time and stops suddenly.
If someone has developed tolerance and/or dependence on a prescription medication taken for a legitimate medical condition, they need to be monitored closely by a healthcare provider. They could require a different dosage or be advised to switch to a different medication, but this doesn’t mean that they are suffering from a substance use disorder.
It is also possible for someone to suffer from addiction without developing tolerance or dependence. For example, if you begin using marijuana to cope with feelings of stress and anxiety, you can be mentally dependent upon the drug as a coping mechanism without experiencing physical signs of tolerance or dependence. However, a mental addiction is still as problematic as one that is accompanied by physical dependence and tolerance.
Common signs of addiction include:
- Lying about substance use when friends and family express their concern
- Having trouble performing in work or school due to youth substance use
- Ignoring social activities you once enjoyed to have more time to engage in substance use
- Having your thoughts preoccupied with substance use and making sure you have a steady supply of the abused substance
- Doctor shopping to get prescriptions
- Overspending or stealing to obtain money for addictive substances
- Engaging in risky behavior, such as unsafe sex or driving while impaired
Addiction is statistically more common in men and people with a family history of substance use disorders. However, people of all backgrounds can develop addiction.
Addiction is treated with counseling to address the underlying issues contributing to substance abuse while helping to promote the development of healthy coping mechanisms to deal with emotionally challenging situations. Although addiction is considered a chronic illness, treatment is effective at all ages and stages of life.
Principles of Drug Addiction Treatment: A Research-Based Guide (Third Edition). National Institute on Drug Abuse.
Drug addiction (substance use disorder). Mayo Clinic.