You have asked an intriguing and difficult to answer question. From my research and personal experience, it is my contention that individuals with schizophrenia are no more dangerous than the average person except when they are actively psychotic, unmedicated, unable to recognize that they are ill and are using drugs and alcohol. Your friend has all four of these risk factors simultaneously putting him at a high risk for violence. This in no way means that he will become violent towards you; it only means that he has an increased risk for becoming violent. Another helpful indicator in determining his risk for violence is whether or not he has acted out violently towards others in the past. Studies show that past violence is a good predictor of future violence. The other risk involved with your friend is that he may also try to harm himself.
The truth of the matter is that it is extremely difficult and practically impossible to predict your friend’s future behavior towards you, himself or anyone else. What is most important in this situation is trying to get him into treatment. I realize that this is a monumental task, one in which you may not be up to fighting. Civil commitment laws in most states make it nearly impossible to for someone like your friend to get help BEFORE something bad happens. It is almost always the case that something bad has to happen before an individual would be eligible for psychiatric help.
Despite this, I would strongly encourage you to try to get him help before he hurts himself or someone else. If you are not willing to try to get him help, then I would advise you to take extra precautions (as you are already doing) and to call the police anytime you feel it is necessary. I am not telling you to call the police to have him arrested; it is just that the police, in many communities, are often the first-line responders in situations regarding individuals with psychiatric disorders. Police show up at the scene and call for help usually from trained, mental health crisis assistance teams. The mental health crisis teams try to get individuals into treatment and are trained to work with individuals just like your friend. I hope this helps to answer your question. Please write again if you have any more questions or needed further clarification about my answer. Take care.
This article has been updated from the original version, which was originally published here on March 16, 2007.