Substance use disorder: dependence is not addiction
Defines substance use disorder (SUD), its severity levels and hallmarks, and separates physical dependence (tolerance and withdrawal) from the disorder itself.
Where this fitsConnects to 2 · Unlocks 1
- Connects to
- Acute and chronic effects: up- and down-regulation — Physical dependence is receptor up- and down-regulation.
- The course lens: biopsychosocial, and no 'chemical imbalance' — Comorbidity and the biopsychosocial lens shape how SUD is diagnosed and treated.
- Unlocks
- The reward circuit: reinforcement and dopamine — Next: what happens in the brain to produce loss of control.
Walk through
One diagnosis, a range of severity
DSM-5 replaced separate 'abuse' and 'dependence' diagnoses with substance use disorder, rated mild, moderate or severe. It has specific forms: opioid use disorder, alcohol use disorder, cannabis use disorder and so on.
Analogy and worked example
Analogy: Wearing glasses every day makes you dependent on them — take them away and the world blurs (withdrawal). Nobody calls that a disorder. It becomes a disorder when the thing has taken over your life: you can't stop even though it's costing you your job and relationships, and you think about it constantly.
A patient has taken prescribed oxycodone for two years for back pain. If they miss doses they feel sick. They take it exactly as prescribed and function well. Do they have opioid use disorder?
- Tolerance and withdrawal are present → physical dependence.
Tip: the ← and → keys move through the lesson.