Self medicating with drugs and alcohol is very common in people with all types of psychiatric disorders. I would expect that a bunch of schizophrenics who have

Self medicating with drugs and alcohol is very common in people with all types of psychiatric disorders. I would expect that a bunch of schizophrenics who have never committed a homicide would have high rates of drug and alcohol abuse in their history. People with less severe symptoms and those getting treatment would be less likely to self medicate. Finding that a bunch of schizophrenics who have committed a homicide have high rates of drug and alcohol abuse isn't surprising either. Because drug/alcohol use can impair people's judgement/inhibitions in the best of circumstances it could be a factor in attacks by schizophrenics, but considering that there are vast numbers of people with who take drugs to excess and very few of them commit homicide I wouldn't jump to putting all the blame on the booze and weed. I'd think that it has a lot more to do with severe cases self-medicating and the lack of treatment.