Marijuana (THC) use may increase the frequency of sleep paralysis.

“One is marijuana, THC, a I'm not a marijuana smoker. I'm not a copper. I don't know the legality where you live. So I'm not saying one thing or another about marijuana. I'm just, the fact that I had that experience without marijuana means that it can happen regardless, but marijuana smokers, for whatever reason maybe it has something to do with the cannabinoid receptors or the serotonin receptors downstream of the motor pathways. I don't know. I couldn't find any literature on this but marijuana smokers report, higher frequency of this kind of paralysis and wakefulness as you transition from sleep to wakefulness.”