Dopamine/Caffeine Question

[IThinkImInTorture]

If low dopamine could be a cause of RLS and Caffeine increases dopamine then why does coffee make RLS worse?

[Rustsmith]

The "cause" of RLS is not low dopamine. Our need to move symptoms are due to an insufficient number of functioning dopamine receptors. If you think of the receptors as locks and dopamine as the keys, we don't have enough locks that are working properly, but loads of keys (dopamine). Yes, we can take a dopamine agonist and this helps our symptoms (for a while). But continuing the lock-key analogy, if you add more keys to your key ring, it increases the chance of finding a key to operate the lock. As for caffeine, it's role in RLS isn't via increasing dopamine. The current theory of how RLS works involves our iron deficiency and alteration of our adenosine receptors. Caffeine interacts with the adenosine receptors and keeps them from working correctly. This is why caffeine wakes most people up and/or prevents them from sleeping. For us, blocking the small number of adenosine receptors that we have that still work just blocks our dopamine and glutamate receptors too. Yes, that is all very confusing and not completely correct when it comes to the exact scientific mechanism, but the key takeaway is that we have already have too much dopamine (and glutamate), so anything that further increases either one of these will just mess us up even more.

[debbluebird]

Steve, I like that explanation. Thanks