Should schizophrenics be forced to have treatment?

Just a short post really, I may add to this at a later date because I think its an interesting topic.
It was a question raised in my psychology class when we were learning about schizophrenia drug therapy and I thought it was very thought-provoking.
What if an individual wants to refuse treatment? If they choose the voices in their head that is telling them they are god (if, say, they had delusions of grandeur and religious auditory hallucinations) over the horrific side effects that make them feel like the walking dead, is that okay? 
Although this promotes choice, it also could be very dangerous. Take, for example, the case of British paranoid schizophrenic Nicola Edgington who killed her mother in 2005, then went on to attack two strangers in 2011, after being released from treatment in 2009. Cases like this suggest that treating schizophrenics is in the public's best interest and serves as a protective measure. 
It is also worth mentioning that it seems like a social norm that schizophrenics should be treated for their disorder. There are schools of thought nowadays that argue that people with mental disorder should not be treated differently and 'who are doctors to say that someone is not normal?' Just because someone acts differently and deviates from a social norm, does this mean they are 'mad' or their behaviour is 'wrong'? There seems to be many sides to this story.