The difference between addiction and dependence can be difficult to understand. Some organizations have different definitions, use the words interchangeably or even abandon both terms altogether. (“Substance use disorder” is a preferred term in the scientific community.) Because of this lack of consistency, some ground rules can help differentiate between the two terms.
When people use the term “dependence,” they are usually referring to a physical dependence on a substance. Dependence is characterized by the symptoms of tolerance and withdrawal. While it is possible to have a physical dependence without being addicted, addiction is usually right around the corner.
Addiction is marked by a change in behavior caused by the biochemical changes in the brain after continued substance abuse. Substance use becomes the main priority of the addict, regardless of the harm they may cause to themselves or others. An addiction causes people to act irrationally when they don’t have the substance they are addicted to in their system.
Addiction encompasses both a mental and physical reliance on a given substance.
Mental Dependence vs. Physical Dependence
Mental dependence is when use of a substance is a conditioned response to an event or feeling. These are known as “triggers.” Something as simple as the act of driving can trigger a desire to use. These triggers set off biochemical changes in a person’s brain that strongly influence addictive behavior.
Triggers can be emotional responses to events, certain people, places or anything a person associates with using a substance.
Symptoms of triggers may include:
- Tightness of the stomach
- Feeling intense desire or need to use drugs or alcohol
- Nervousness or anxiety
When the symptoms of mental and physical dependence are apparent, an addiction is usually present. However, the main characteristic that distinguishes addiction from dependence is the combination of mental and physical dependence with uncontrollable behavior in obtaining and using a substance.
So, why do some organizations scrap the word “addiction” from their vocabulary? The DSM believes the term carries too much negative connotation and is ambiguous. The World Health Organization also wanted to replace the medical designation of “addiction” with the word “dependence” back in 1964 (which probably contributed to the confusion).
‘Substance Abuse’ vs. ‘Substance Dependence’
The Diagnostic and Statistical Manual of Mental Disorders (DSM) is the leading source for diagnosing and understanding addiction. The DSM-IV defined abuse and dependence as two separate disorders. However, the most recent edition of the DSM no longer creates this distinction.
Abuse and dependence are defined on a scale that measures the time and degree of substance use. Essentially, abuse is like the early stage of dependence. As substance abuse becomes more frequent, the likelihood of developing a dependence disorder becomes greater.
Abandoning the Terms
In 2013, the American Psychological Association (APA) released the fifth edition of the DSM. In this edition, the definitions revolving around addiction were changed once again. The APA ditched both “substance abuse” and “substance dependence” in favor of “substance use disorder.” Substance use disorder is now the medical term for addiction. Previously, abuse was a mild form of addiction, and dependence was a moderate or severe form of addiction. That terminology was problematic because in biology — the study of organisms — dependence refers to a physical adaptation to a substance.
Today, the APA classifies substance use disorders as mild, moderate, or severe. It doesn’t use the terms abuse and dependence to categorize the severity of an addiction. Part of the reason for the change was the confusion surrounding the word ‘dependence.’ The hope is that defining an addiction as a substance use disorder was a more inclusive way to identify people who need help, but may not have a debilitating addiction.