Is there a word or phrase to express the concept of an action having the opposite effect of the expected outcome?
For example, a drug taken to cure headaches that actually causes headaches, or an advertising campaign designed to deter smoking that leads to an increase in smoking.
A common idiom expressing this concept is "to backfire". For example:
Counter-productive seems to fit your request pretty closely. The OED defines it as:
Having the opposite of the desired effect, tending to act against the attainment of an objective.
It’s a comparative neologism (apparently originally from US bureaucrat-speak in the 60’s), but is now well-established on both sides of the Atlantic in both formal and informal use:
The drug laws are counter-productive, and David Cameron knows it.
— Tom Chivers, in the Daily Telegraph
But you’re right, they wouldn’t sue him (even if they had a case) because it’d just be counter-productive.
— lightlee.tumblr.com [random Google result looking for casual use]
I believe this may also be considered irony; specifically situational irony.
Such situations could therefore be described as ironic, but probably only upon second reference, when the facts of the matter had already been established.
e.g.:
First mention: The headache-treating drug was known to have caused headaches.
Second mention: Dr. Stephens reported the drug's ironic effect to the FDA.
It's called a Paradoxical Reaction. In general terms, I think you call something like that a paradox.
I just found this term recently and thought that it will be useful for somebody:
The Streisand effect is the phenomenon whereby an attempt to hide or remove a piece of information has the unintended consequence of publicizing the information more widely, usually facilitated by the Internet.
[Wikipedia]
This term is now specific to mass media / Internet, but it will be possibly penetrating in the other relevant fields. However, general concept here is a bit more specific here: forbidding something can possibly rise an interest in something and thus cause a more wide spread (i.e. an opposite effect of intended action).
Macmillan Dictionary: do someone/something a disservice/do a disservice to someone/something
to do something that makes people’s opinion of someone or something not as good as it should be To describe her as just a journalist is to do her a disservice. He is doing himself a disservice by allowing his songs to be so badly performed.
