Beyond the semantics, this is what the meta analysis(1) actually says in the abstract

> There were insufficient data to meta-analyse studies of ADHD, bipolar disorder, obsessive-compulsive disorder, and tobacco use disorder. There was an absence of RCT evidence for the treatment of depression. Meta-analysis revealed higher odds of all-cause adverse events (OR 1·75, 95% CI 1·25 to 2·46) among those using cannabis versus control group

The paper says there's no evidence of effectiveness in treatment, and evidence of harm.

1: https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0...