MORE ON REBOUND HEADACHES: Reader Ann Scher emails:

I am longtime reader of your web site and was inspired to comment on your link to the NYT article on rebound headache.

I am a headache researcher (epidemiologist) and have an interest in this particular topic. There is some debate on the degree to which medication “overuse” aggravates headache and, in my opinion, much of the published data purporting to support this concept suffers from various methodological flaws.

Regarding rebound headache (the preferred term is now “medication overuse headache”) – to my knowledge, the only substance shown to cause an actual rebound headache in a blinded placebo-controlled trail is caffeine. However, rebound headache is a presumably short-lived phenomenon and it is not obvious, at least to me, how caffeine withdrawal headache would lead to chronic daily headache lasting for months or years on end as it does in some people.

My concern is the following: If medication overuse is not really an aggravating factor for chronic daily headache or is an aggravating factor in only a minority of people, the advice to limit treatment to a few days a week is leading to the undertreatment of pain.

Good point. Earlier post here.