The terms “Dependence”, “Tolerance”, “Addiction”, and “Withdrawal” are all common when discussing medicines, substances and recovery.

It is easy to be confused about what these different terms mean, especially as there is a degree of crossover between them. In this article, we look at the differences in these terms.

Dependence, tolerance, addiction and withdrawal are all important areas

What is dependence?

When a person takes certain substances, drug dependence can result in them feeling like they are unable to function normally without taking said substance.

For example, a long-term user of Benzodiazepines like Alprazolam (Xanax) may find that after three months of taking the drug, they are unable to stop it easily. Instead, they will feel like they cannot function without taking Alprazolam.

Dependence can have a significant impact on a person’s life, as well as those around them. As the term suggests – a person can literally become dependent on a substance to see them through the day.

What is tolerance?

Drug tolerance meanwhile refers to the process where the body gets used to a substance over a period of time. When a person develops a tolerance, they will need to take higher doses of the substance in order to experience the same effects.

Sticking with Alprazolam as an example, a person may initially start on a low dose of 2mg/day. At first, this is likely to help the person. But after taking this same dose for a couple of weeks, the person may feel as if they are not getting the same effects.

Therefore, in order to achieve the same effect, the person may start taking a higher dose of Alprazolam. This can trigger a vicious cycle where a person needs to take higher and higher doses to achieve what they want. This then results in them becoming dependent on the substance, as discussed above.

Drug tolerance can creep into a person’s life alarmingly easy. It can be a terrible thing and start a cycle that ends up with full-scale addiction. Many people that take opioid medications fall into this trap.

What is addiction?

Drug addiction is the state where a person is unable to stop taking a substance. This might be because they feel unable to function without it (dependence), or simply crave it. They will continue to try and take the drug even though it causes negative effects on their life.

Tolerance and addiction are very similar. However, tolerance refers to the process where the body gets used to a substance, while addiction involves a person being unable to control their use of the substance.

Continuing with the example of Alprazolam, a person may feel they are unable to stop taking Alprazolam. Whenever they have gone more than a few hours without taking it, they crave another dosage.

Addiction is a terrible thing that can ruin lives. Drug addiction is a serious problem. If it is not treated, then serious medical problems and even death is possible.

What is withdrawal?

Drug withdrawal refers to when a person tries to withdraw from a drug. This is typically done after a person tries to “get clean” from the substance they have been taking.

However, it is also important to note that withdrawal takes place with any medicine. For example, those that take antidepressants and later stop will go through a withdrawal process. Some substances are harder to withdraw from than others.

When withdrawing, a person may find it easy, or difficult – typically depending on the substance involved. If a person is addicted to a drug, they will often have terrible withdrawal symptoms – such as flu-like symptoms, headaches, chills, and mental health problems.

Withdrawal can be very difficult. Because of how difficult it can be, it leads to many people relapsing and start taking the substance again – restarting the cycle.

A typical process

These four areas are all interlinked. When a person takes a substance that has addictive characteristics, their body can quickly develop a tolerance to it.

They can subsequently become dependent on the substance. At this point, it is likely an addiction has formed. Despite trying to get off the drug, they find they are unable to do so.

When they do try, they get terrible withdrawal symptoms. This can make their addiction worse, and cause a range of physical and mental health problems.


As seen above, there is definitely an element of crossover between these various areas. Regardless of what stage a person is in, it can be a tumultuous ride.

Some people find that a form of talking therapy can help with underlying issues behind substance abuse problems.

Ultimately though, many people find that a detoxification process is needed. Drug detoxification is a difficult process, but can be rewarding.

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