I think that there is also necessary a prevention of “marijuana problem”, because it seems that cannabis use can precipitate schizophrenia in “vulnerable individuals”, especially. The goal of my comments is to show that cannabis use can be a cause of schizophrenia; characterize two effects on NMDA hypofunction, related to schizophrenia-associated neurodegenerative impairment. See also website www.bse-expert.cz , chapter; Hyperfunction (Alzheimer’s disease and Parkinson disease) and hypofunction (schizophrenia) of glutamatergic neurons