Ex juvantibus
Encyclopedia
The term ex juvantibus refers, in medical contexts, to the process of making an inference about disease causation from an observed response of the disease to a treatment.
For example, taking the case of a patient whose headache had been alleviated by taking aspirin, an ex juvantibus line of reasoning would state that the headaches were caused by low levels of aspirin in the brain. Obviously, the fact that aspirin cures headaches does not prove that headaches are caused by the absence of aspirin. In "The 21-Century Brain" (2006), Steven Rose
applies the term to the use of psychoactive drugs to "cure" depression, implying that the underlying cause of depression is not simply low levels of certain chemicals in the brain (such as serotonin) that these drugs treat.
The phrase does not necessarily connote a fallacy. For example, a patient presents with retrosternal pain which is not relieved by sublingual nitrates (a standard remedy for angina pectoris) but is relieved with antacid
s (a standard remedy for heartburn
). In such a case, a physician may hypothesize ex juvantibus what the underlying problem may or may not be, until a definitive diagnosis is established.
For example, taking the case of a patient whose headache had been alleviated by taking aspirin, an ex juvantibus line of reasoning would state that the headaches were caused by low levels of aspirin in the brain. Obviously, the fact that aspirin cures headaches does not prove that headaches are caused by the absence of aspirin. In "The 21-Century Brain" (2006), Steven Rose
Steven Rose
Steven P. Rose is a Professor of Biology and Neurobiology at the Open University and University of London.-Life:...
applies the term to the use of psychoactive drugs to "cure" depression, implying that the underlying cause of depression is not simply low levels of certain chemicals in the brain (such as serotonin) that these drugs treat.
The phrase does not necessarily connote a fallacy. For example, a patient presents with retrosternal pain which is not relieved by sublingual nitrates (a standard remedy for angina pectoris) but is relieved with antacid
Antacid
An antacid is a substance which neutralizes stomach acidity.-Mechanism of action:Antacids perform a neutralization reaction, increasing the pH to reduce acidity in the stomach. When gastric hydrochloric acid reaches the nerves in the gastrointestinal mucosa, they signal pain to the central nervous...
s (a standard remedy for heartburn
Heartburn
Heartburn, also known as pyrosis or acid indigestion is a burning sensation in the chest, just behind the breastbone or in the epigastrium...
). In such a case, a physician may hypothesize ex juvantibus what the underlying problem may or may not be, until a definitive diagnosis is established.