One anecdotal data point against increased creativity is that drug users tend to exhibit stereotypical behaviour. It’s usually possible to tell if someone has been using cocaine or marijuana or MDMA or LSD after only a few minutes of interacting with them and with limited experience of the drug in question. The behaviour is also typically unimpressive. I don’t recall ever encountering somebody using any of the aforementioned drugs doing anything atypically creative.
One anecdotal data point against increased creativity is that drug users tend to exhibit stereotypical behaviour. It’s usually possible to tell if someone has been using cocaine or marijuana or MDMA or LSD after only a few minutes of interacting with them and with limited experience of the drug in question. The behaviour is also typically unimpressive. I don’t recall ever encountering somebody using any of the aforementioned drugs doing anything atypically creative.