I would re-arrange the negatives list to put the clear facts first, and the speculative facts after. For instance, the list should start with the obvious truth that "Smoking cannabis causes carcinogens to enter the body." However, I would even go so far as to amend that with something like, "However, alternate methods of consumption (such as oral) do not involve carcinogen exposure."
Several could be reworded to accomodate Nuksy's guideline of indicating that the pot does not necessarily cause mental conditions but can simple exacerbate or draw out dormant or latent conditions.
My prime example would be:
"In some cases high quantity users can experience feelings of anxiety, depression and be seriously unwell."
That should read something like, "As with any other active substance, people with conditions such as anxiety or depression may find their symptoms exacerbated by use."
Also:
"During pregnancy, cannabis can have negative consequences for the fetus." <--I am not convinced that htis is documented at all. I believe what you want to say here is, "smoking anything" instead of "cannabis".
And I think you should separate the below list into a separate bullet point list so that it is more clear that you are listing speculation and not fact:
Some researchers are of the opinion that:
Cannabis is a first step to the use of hard drugs.
Cannabis has negative effects on the immune system.
Cannabis influences fertility.
Cannabis causes schizophrenia.
More.
Cannabis leads to apathy and loss of interest.
Cannabis can cause anger, especially when trying to stop using Cananabis.