to start, this is a meta analysis of 54 studies. not a great start

second:

54 trials were identified for inclusion (2477 participants; 1713 [69%] males, 764 [31%] females; median age 33·3 years [IQR 28·1–38·05; ethnicity data not available). 24 (44%) of these trials had a high risk of bias, and the certainty of evidence for most outcomes was low. [emphasis added]

so, this is a huge red flag already. when almost half of the studies are categorized as "high bias" and have a low certainty of evidence, that's pretty bad.

There was some evidence that cannabinoids can reduce symptoms of cannabis use disorder, insomnia, tic or Tourette's syndrome, and autism spectrum disorder, but the quality of this evidence was generally low. Cannabinoids were associated with a greater risk of any adverse events but not of serious adverse events. Overall, there is a crucial need for more high-quality research. Given the scarcity of evidence, the routine use of cannabinoids for the treatment of mental disorders and SUDs is currently rarely justified.

so, the conclusions of this meta analysis is that many of the studies they reviewed were unreliable, biased crap and that they can't really draw much of any conclusions from them as little reliable evidence was contained within except for the evidence that more, newer high-quality studies are obviously needed.

lol

thanks for the link to the study, though. it was very amusing