Imaginary playmates are not rare. They typically occur in children who are functioning very well. They don't cause a disturbance at home. They're often quite pleasant, and the child finds this something entertaining. … But [with schizophrenics] these voices are usually quite strange. The child will be looking often up, say at the ceiling, and talking and laughing in a way that seems quite inappropriate.
A lot of the time, the children will say that they have voices that are telling them very unpleasant things. Voices tend to be there almost all the time, and if you are living with a child, the families often report that they can hear them talking all the time. It just doesn't have the same feel, and often the voices are telling them very bad things—talking about death, talking about things that a child should do or that might be done to them.
A very good website to read good Childhood Schizophrenia stories is this: