I always thought a discovery was always existed and an invention was the building of some thing from different components, compounds etc.LSD was not one single ingredient but a group combined to form L.S.D.Not a single ingredient that was discovered....hence an INVENTION.
I’m pretty sure that while LSD-like compounds exist in nature, when Hofmann was experimenting and “discovered” it, it was one of a number of substances which had been synthesized. Thus, describing it as an invention would not be entirely inaccurate. In much the same way, although salicylic acid exists naturally in willow bark, for example, ASA was an invention of chemists, who synthesized it from, IIRC, coal tar.