Addiction vs. Dependence

The definitions of addiction and dependence in the context of substance use disorders are different. Substance dependence includes physical or physiological symptoms, such as increased tolerance and withdrawal symptoms. Dependence is almost purely physical; it has to do with how the body responds to repeated drug or alcohol use. Rather than your brain telling you that you need more of the substance in their system, your body tells you it will not feel normal without alcohol or drugs. Dependence can be mental as well, but differently than addiction.

Despite the difference in their definitions, dependence and addiction are not always mutually exclusive. It is possible to have a physical dependence on a substance without being addicted, but dependence is almost always an addiction factor. While a dependent person is not yet addicted, it is possible they will be.

Addiction is not as clear-cut as the definition of dependence, but the main difference is that addiction has to do with changes in the brain. When the brain’s biochemistry adapts to substance use so that a person is compulsively using despite harmful consequences, a person is considered addicted. No matter what they do or what harm their substance abuse can cause themselves or others, they cannot stop using the drug.

Addiction is not a conscious choice—when substances take control of the brain’s pleasure centers and dopamine transmitters, it slowly unlearns how to produce those feelings independently. Therefore, substance use becomes essential to brain functioning in a way out of the individual’s control. While dependence constitutes a physical reaction to substance abuse, addiction will change behavior. The substance becomes the number one priority; a person’s thoughts will revolve around obtaining the substance. Addiction encompasses the mental aspect of substance abuse disorder that dependence does not.