What causes schizophrenia? They say that this to cancer and mental illness. If you don’t treat this it can lead you to suicidal. Studies show that in twins, if one develops schizophrenia the other is 4 times more likely to develop schizophrenia as well if they are identical as opposed to non identical twins. Children who are adopted (and so not in the biological family environment) are also much more likely to develop schizophrenia if a biological parent has the condition too. However, the genetic influence is not clear-cut and other