Psychology
Antidepressants: what they do, side effects and stopping safely
What antidepressants treat, how long they take, common side effects, whether they are addictive, and why you should never stop them suddenly.
27 Sept 20268 min read
Placebo
Pronounced pluh-SEE-boh
Also known as Dummy treatment, Placebo effect
A placebo is a treatment with no active ingredient, used in trials as the comparison against which a real medicine is judged. The placebo effect is the genuine improvement people report after receiving one.
Illness rarely stays level. Symptoms fluctuate, most self-limiting conditions improve on their own, and people tend to seek treatment when they feel worst — so some recovery would have happened whatever was given. Add the effect of attention, expectation and the ritual of being treated, and a proportion of any improvement after a treatment has nothing to do with the treatment.
That is why the placebo exists as a control. A trial compares the medicine against an identical-looking dummy, and neither participant nor assessor knows which is which. The question the trial answers is not "did people get better?" but "did they get better than the people who received nothing active?" — and a great many plausible treatments have failed exactly there.
The mirror image is the nocebo effect: someone told to expect a becomes more likely to report it, which is one reason side-effect rates in the placebo arm of a trial are almost never zero.
Where this comes up
Psychology
Placebo and nocebo effects: how expectations change symptoms
Expecting to feel better can ease pain and nausea; expecting side effects can cause them. Neither cures disease — and both matter in the clinic.
27 Sept 20267 min read
Gastroenterology
Irritable Bowel Syndrome: When the Gut Hurts but the Tests Are Normal
IBS is a real disorder of how the gut and brain communicate, not nerves or imagination. Diagnosis is positive rather than a process of exclusion, and several treatments work.
19 Aug 20269 min read
Orthopedics
Knee Osteoarthritis: Why It Hurts and What Genuinely Helps
Worn knee cartilage is common after 45 and rarely means surgery is coming. Exercise and weight carry more evidence than any tablet, injection or supplement.
11 Aug 202610 min read
Related terms
- Side effectAdverse effect, Adverse drug reactionA side effect is any effect of a medicine other than the one it was given for. Some are trivial and settle, some are the reason a medicine has to be stopped.
- ScreeningScreening testScreening is testing people who feel well, to find a condition earlier than symptoms would. It is only worth doing when finding the condition early genuinely changes what happens next.
- PrognosisOutlookA prognosis is the expected course of a condition — how it is likely to develop and what the chances of recovery are. It is a statement about probability across many people, not a prediction about one.
- RemissionRemission means the signs and symptoms of a disease have reduced or disappeared. It is not the same as cure — the condition may still be present and can return.