A fascinating read on the subject:
Quoted from
Role of serotonin in memory impairment - PubMed :
"Converging evidence suggests that the administration of 5-HT2A/2C or 5-HT4 receptor agonists or 5-HT1A or 5-HT3 and 5-HT1B receptor antagonists prevents memory impairment and facilitates learning in situations involving a high cognitive demand. In contrast, antagonists for 5-HT2A/2C and 5-HT4, or agonists for 5-HT1A or 5-HT3 and 5-HT1B generally have opposite effects."
That's an example of some receptor-specific findings, but still much is unknown with regard to how complex and intricate Serotonin's role is in memory and learning.
LSD is a very strong selective agonist of 5HT (Serotonin) 2A receptors. Anyone trying to claim LSD impairs memory and learning fuctions is spreading propaganda to claim the very opposite of reality. I know this to be fact from both published research and personal experience. Similar (but each a bit different ofc) activity is seen with other serotonergic drugs such as DMT, mescaline, psylocin, and 2c-b.
The opposite is true of DXM. Take a high enough dose, and it is neigh impossible to create new short-term memories until the effect of the DXM has worn off. Very difficult to focus, best of luck learning anything, but yet cognitive actions such as typing/writing/playing guitar are rather easy as long as you don't try to focus on what you're doing. Surely there's some type of feedback problem (much like the visual flanging of input that can happen similar to a TV-camcorder feedback loop) with hyperactive receptors responsible for short-term memory going on to explain that phenomenon.
Cannibinoid research has a long way to come in regard to marijuana's effect on memory. Substantial claims can be made that Cannabinoid effects on attention span (which no mj user can deny) is more to blame for a seemingly reduced short-term memory capacity. Ask any gamer who smokes pot - are they more skilled at real-time strategy games while stoned or not? Myself and all others I've talked to will say RTS skill comes easier while stoned, and strategizing in real-time requires a whole lot of short-term memory usage.
All that said, my memory these days is quite near what it should be. I have Celebrex to thank for my woes in this regard. Nasty stuff. Works wonders for ruptured disc inflammation, but completely not worth the risk of up to 8 years of short-term memory impairment. Several time frames spanning 12 to 24 months of complete sobriety with no memory improvement allow me to claim that the use of some aforementioned drugs have actually helped revert the memory effects from the NSAID.
