PLACEBO - NOCEBO

There is a wealth of medical research literature showing how pervasive and common is placebo and nocebo response to drugs and other forms of medical treatment.

In a stomach cancer controlled trial, nearly a third of the placebo-treated group lost their hair, and over half had nausea or vomiting[1].

More than two-thirds of an unselected group of healthy students reported[2] mild headache when told a nonexistent electric current was being passed through their heads. The effect occurred whether the students were concentrating on symptoms or their attention was on a perceptual task, with the headache as only a possible incidental effect.

PRACTICE POINT Placebo and Nocebo reactions are a part of the human condition and must be considered in every Personal Injury and Medical Negligence action

Mildness of illness and married status were the strongest predictors of placebo response in an antidepressant medication study[3]. The elderly were more likely to experience non-pharmacological benefit, and there was an overall excess of men over women responders. Educational level and duration of illness had no detectable effect.

Personality type appears to be a determinant of Nocebo response. 50% of a group of competitive and aggressive (Type A) healthy volunteers reported adverse symptoms after placebo pills, in contrast with only 17% with Type B personalities[4].

Placebo pain relief involves both the production of internal narcotics (endogenous opioids) and the activation of nerve pathways from the brain which block the transmission of painful nerve impulses[5]. Conversely, nocebo response is thought to result from activity in the locus coeruleus of the brain stem. The chemical messenger neurotransmitters are dopamine and noradrenaline respectively.

Copyright © 2008 Electronic Handbook of Legal Medicine