About 4 years ago I initiated a nearly 6 month long string of panic attacks and having anxiety to point of feeling completely dead by consuming half of a caffeine tablet. That was the last time I consumed any amount caffeine. Caffeine is, of course something anyone with panic related disorders should avoid, and for me it was the agent that made me have panic in the first place, and I learned quickly. Anywho, I was doing some research about adenosine last night, because I wanted to know a bit more about SAH and its inhibitory effects on methylation, and how adenosine plays a role in that. Apparently high levels of adenosine will inhibit SAHH function and will cause higher levels of SAH to potentially inhibit SAMe. Caffeines primary mechanism of action is as a adenosine receptor antagonist. Now caffeine does a whole bunch of things that could potentiate a panic attack as a result of this, increasing nuerotransmission all around, and increasing adrenaline output (a biggy I think), and inhibiting GABA as well. Besides all this, I wondered what kind of impact caffeine could have on methylation. Would its antagonism of adenosine receptors cause a higher levels of adenosine that would inihibit SAHH function? I found this article which discusses adenosine plasma levels as a result of caffeine intake. (http://wurtmanlab.mit.edu/static/pdf/921.pdf). I don't know if plasma adenosine levels impact SAHH or not, as I am not quite sure where the methylation reactions occur. Here is another interesting article about the synthesis of caffeine in caffeine containing plants. Apparently its synthesis requires methylation and flows down the adenosine metabolic pathway, no wonder it is mistaken for adenosine in our bodies. (http://www.sciencedirect.com/science/article/pii/S0014579301025121) Caffiene can also be referred to as trimethylxanthine, as there are 3 methyl groups attached to it. I read somewhere else that it can act as a methyl donor as well by donating methyls in the liver. So it seems to me that caffeine could potentially impact methylation negatively and positively in different ways. I just wanted to share this info because I thought it seemed interesting while reading about it.