Therapeutic effect

A therapeutic effect is a consequence of a medical treatment of any kind, the results of which are judged to be desirable and beneficial. This is true whether the result was expected, unexpected, or even an unintended consequence of the treatment. An adverse effect, on the other hand, is a harmful and undesired effect.

What constitutes a therapeutic effect versus a side effect is a matter of both the nature of the situation in which a treatment is used and the goals of treatment. There is no inherent difference between therapeutic and undesired side effects; both responses are behavioral/physiologic changes which occur as a response to the treatment strategy or agent. However, those changes which are viewed as desirable, given the situation, are called therapeutic; those undesirable for the situation are viewed as harmful.

Many people think of therapeutic and undesired side effects as only applying to medications, drugs or supplements, perhaps because pharmacology approaches are more often more rigorously evaluated by carefully controlled comparisons with placebo treatments, but this is not the case. It applies to any treatment approach, including surgery, physical therapy, psychotherapy, treatment with compounds, faith healing, hypnosis, holistic methods, etc.; any method of which one can conceive.

The administration of a compound was selected for the pharmacologic example below because this form of treatment is often more readily evaluated by comparison with a placebo approach; the comparison designed so that people are unable to recognize the difference, at least at a conscious or group awareness level. Other therapeutic methods are typically more difficult to test because the test subjects can more easily recognize the key aspect of treatment which is being tested; it thus becomes far more difficult to apply the placebo control methodology. The placebo effect is always relevant in all treatments; behavior and symptoms do change, however the presumed mechanism may primarily be the power of the mind which controls behavior and perception all the time, and the fact that if an individual believes that their situation will change then their situation actually does change.

...
Wikipedia