GABA transaminase inhibitor
We also discussed the GABAergic mechanisms a bit in this thread:
Melissa officinalis (Lemon balm) mechanism of action.
Some people seem to use MO as a nootropic, but I would classify it first as an anxiolytic. I find it sedating and emotionally flattening, which makes sense if it potentially increases GABA. I guess its usefulness would depend on an individual's reaction to these two systems. For instance,
this study found that 600mg enhanced attentional scores, but decreased working memory, secondary memory, and alertness.
There was an interesting implication in
this study, which I didn't catch before: with doses of 600, 1000, and 1600mg, only the largest was found to have an "overwhelmingly favorable" profile of cognitive enhancement, with decreasing dosage producing decrements in processing speed and memory. I could speculate that the increase in GABA reaches a ceiling at a certain dose; only a certain portion of GABA-T can be inhibited (even if it's all of it), for a certain amount of time. And presynaptic GABA-B autoreceptors will limit the amount of synaptic GABA. However, the cholinergic effects might be expected to be a little more linear in dose-response, so higher doses could produce an effect that balances or outweighs the GABA inhibition. Just a theory to explain that result, of course.
I grind up the herb in a ribbed mortar, and take it in capsules. I also use a stainless steel tea ball sometimes, for higher dosages. I've played with 100-600mg doses for sedation/anxiolysis; usually 100-200mg if I'm trying to reduce stress while studying. Given my speculation above, I'll probably try a 1.5-2g dose sometime soon, when I can afford to be zonked out if it doesn't work.
