Psychology
What is The nocebo effect?
The nocebo effect is the placebo effect's negative twin: when negative expectations cause real, harmful symptoms. If you expect a treatment to cause side effects, you may genuinely feel them — even from a harmless sugar pill.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains the nocebo effect.
Key things to understand
- 1Negative expectations can produce real symptoms.
- 2It's the opposite of the placebo effect.
- 3Even harmless substances can trigger side effects.
- 4It shows how powerfully the mind affects the body.
Frequently asked questions
- What is the nocebo effect?
- When negative expectations cause real, harmful symptoms, even from a harmless or inactive treatment.
- How is nocebo different from placebo?
- Placebo brings benefit from positive expectation; nocebo brings harm from negative expectation.
- Why does the nocebo effect matter in medicine?
- Warning patients of side effects can sometimes cause those very symptoms through expectation.