Physical dependence is where your body requires opioids to prevent withdrawal. OUD involves an addiction governed by the brain’s reward center, along with problematic patterns of opioid use.

It’s partly about control. Someone with a physical dependence on opioids may have some level of control over their opioid use.

Substance use disorders, on the other hand, affect the part of the brain that guides self-control to the point where a person might prioritize drug use over their safety and quality of life.

OUD involves not just physical dependence but also significant behavioral, psychological, and social problems stemming from opioid use.

Someone with a dependence on opioids may develop OUD, but this isn’t always the case.

“Opioid use” is a term given to any instance where people use opioids.

Opioid misuse is when someone uses opioids not as prescribed by a medical professional. For example, they may:

  • take a higher dose than prescribed
  • take doses more often than prescribed
  • use someone else’s medication
  • use illegal opioids, like heroin

In contrast, “correct” opioid use involves using opioids:

  • as prescribed by a healthcare professional
  • for medical reasons, such as temporary pain management after surgery
  • that are legally obtained

It’s important to note that legal prescription opioids, like oxycodone and morphine, can still be misused.

Opioid dependence refers to a state where your body adapts to the presence of the drug, leading to tolerance and withdrawal symptoms if you suddenly stop taking the drug.

Common opioid withdrawal symptoms include:

Dependence is a physiological response. It can develop even when you use opioids as prescribed. However, using more opioids than prescribed can increase your chance of physical dependence.

Dependence is not inherently “bad” and doesn’t always indicate a disorder. Still, it can be unpleasant. You might need a healthcare professional to help you taper off opioid use.

Yes, there is a close relationship between opioid dependence and tolerance.

Tolerance occurs when a person needs a higher dose of opioids to achieve the same effect due to repeated use.

Dependence often accompanies tolerance, as the body becomes accustomed to the presence of the drug and may experience withdrawal symptoms without it.

Opioid dependence and long-term opioid use can occur without OUD. A key difference is the effect on a person’s life.

A person may use opioids for a long period or have a physical dependence without engaging in harmful behaviors or experiencing significant life disruption.

However, OUD involves a range of behaviors that reflect loss of control over opioid use. This can include continued use despite negative consequences and difficulty fulfilling work, school, or home responsibilities.

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR) outlines specific criteria for diagnosing OUD, emphasizing behavioral and psychological aspects of opioid misuse.

These symptoms include:

  • taking larger amounts or for longer than intended
  • persistent desire or unsuccessful efforts to cut down or control use
  • spending a lot of time obtaining, using, or recovering from the drug
  • cravings or strong desire to use opioids
  • inability to fulfill major obligations at work, school, or home
  • continued use despite social or interpersonal problems
  • giving up important activities because of use
  • using in physically hazardous situations
  • continued use despite negative physical or psychological effects
  • developing tolerance and experiencing withdrawal

If you suspect that you or a loved one has OUD, it’s imperative to seek help from a healthcare professional or addiction counselor as soon as possible.

If you or someone you know is experiencing opioid dependence or OUD, there are numerous resources available for help and support.

Consider the following:

Although OUD can be tough to navigate, it can be overcome. Many people manage to recover from OUD and go on to lead fulfilling, functional lives.

Seeking professional help is a critical step in addressing opioid-related issues and finding the right support and treatment.


Sian Ferguson is a freelance health and cannabis writer based in Cape Town, South Africa. She’s passionate about empowering readers to take care of their mental and physical health through science-based, empathetically delivered information.