What is the relationship between caffeine and migraine? Caffeine is used as medicine to abort migraine episodes. Caffeine and caffeine withdrawal are considered to be among the factors that trigger migraine episodes. Abrupt withdrawal from caffeine can cause migraine-like severe headache and nausea/vomiting.

It seems paradoxical that caffeine both triggers and aborts migraine episodes. It also seems paradoxical that caffeine causes migraine-like caffeine withdrawal headaches yet aborts genuine migraine headaches. And it is remarkable that caffeine aborts both migraine-like caffeine withdrawal headaches and genuine migraine headaches.

The mechanism of addiction and withdrawal seems to readily resolve the caffeine paradox: caffeine withdrawal causes migraines, caffeine relieves them by reversing caffeine withdrawal.

According to the prevailing view, however, migraine and caffeine withdrawal headache are two completely distinct and separate conditions. Caffeine and caffeine withdrawal can trigger migraine episodes but not cause them. Caffeine relieves caffeine withdrawal headache by reversing caffeine withdrawal, but relieves migraine headache by some different, unknown mechanism. That is the doctrinal bedrock of the prevailing view of migraine pathogenesis: whatever the mysterious cause of migraine is, it cannot be caffeine.

If the prevailing view is correct, migraine can exist absent caffeine use. It is therefore rather astounding that migraine absent caffeine has never been demonstrated. Which means the prevailing view of migraine pathogenesis entirely relies on an undemonstrated assumption. If the prevailing assumption is mistaken, if caffeine can cause migraine episodes, if migraine is sometimes or always caffeine withdrawal and vice-versa, that would readily explain many otherwise mysterious symptoms and aspects of migraine, including the severe headache and nausea/vomiting, the high prevalence of migraine, the episodic nature of migraine, and the ability of caffeine to abort migraine episodes.

So why haven't migraine researchers produced a demonstrated example of migraine absent caffeine? Mainly because they are satisfied with patient testimony: many migraine patients report caffeine abstinence, and migraine researchers assume such testimony is reliable. But the reliability of such testimony has not been determined. It could be totally unreliable; it may be every migraine patient who reports caffeine abstinence is mistaken. Migraine researchers consider that possibility too unlikely to merit investigation. But that is yet another assumption.

What's needed is a trial study in which migraine patients are instructed to wean themselves from caffeine, their compliance verified by objective means such as saliva tests. Such a trial would clarify the role caffeine plays in migraine.

migraine caffeine withdrawal headache episodic yes yes severe headache yes yes nausea/vomiting yes yes depressed mood yes yes visual aura yes ? one-sided symptoms yes ? photophobia yes ? relieved by caffeine yes yes relieved by triptans yes ? high prevalence yes yes runs in families yes ? caffeine a risk factor yes yes associated with female gender yes ? associated with weekends yes yes