Numerous criticisms have been emerging in the battle against marijuana legalization. Medical and recreational marijuana have been legalized all throughout several states. Having it legalized might be a good thing, but opposing parties however couldn't be avoided. Reports have emerged linking marijuana to schizophrenia as some researchers and opposing parties claimed that pot is capable of causing the mental disorder. These allegations however were proven wrong by several researchers.

As per Leaf Science's report, marijuana does not cause schizophrenia.  Matthew Hill, PhD of the University of Calgary's Hotchkiss Brain Instituted shed light onto the debate on a recent editorial for the Journal of Psychiatry & Neuroscience.

Dr. Hill made it clear on his notes from epidemiological data stating that:

"Within the Western world, cannabis use went from essentially non-existent in the 1950s to extremely prevalent in the 1960s and 1970s. Despite this dramatic shift in cannabis use at a societal level, the prevalence of schizophrenia has largely remained stable."

He then added:

"While many conditions, including lung cancer and cardiac arrthymias, have been at the forefront of the cannabis safety debate for some time, interestingly the discussion has predominantly moved to psychiatry - specifically the association between adolescent cannabis use and the development of schizophrenia."

 PsychCentral then added that a new research conducted at Harvard Medical School finds minimum evidence from marijuana use and its correlation to schizophrenia.  The researched then noted that:

 "The results of the current study suggest that having an increased familial morbid risk for schizophrenia may be the underlying basis for schizophrenia in cannabis users and not cannabis use by itself. Examines both non-psychotic cannabis users and non-cannabis user controls as two additional independent samples, enabling the examination of whether the risk for schizophrenia is increased in family members of cannabis users who develop schizophrenia compared with cannabis users who do not and also whether that morbid risk is similar or different from that in family members of schizophrenia patients who never used cannabis."

In conclusion, not substantial amount of studies have proven that marijuana causes schizophrenia.