I'd challenge you to read those results again. They admit to the evidence for health effects being elusive (due to limited or no robust studies), yet there is still enough evidence to summarize the following:

"

There is substantial evidence of a statistical association between cannabis use and:

The development of schizophrenia or other psychoses, with the highest risk among the most frequent users (12-1) There is moderate evidence of a statistical association between cannabis use and:

Better cognitive performance among individuals with psychotic disorders and a history of cannabis use (12-2a) Increased symptoms of mania and hypomania in individuals diagnosed with bipolar disorders (regular cannabis use) (12-4) A small increased risk for the development of depressive disorders (12-5) Increased incidence of suicidal ideation and suicide attempts with a higher incidence among heavier users (12-7a) Increased incidence of suicide completion (12-7b) Increased incidence of social anxiety disorder (regular cannabis use) (12-8b)"

National Academies of Sciences, Engineering, and Medicine. 2017. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. Washington, DC: The National Academies Press. https://doi.org/10.17226/24625.

I would warrant that these summaries should be a concern for anyone using cannabis and that blanket statements regarding the overall tone and summation of the report negating health effects of cannabis is somewhat misguided.