From Phys.Org:
A 6-year-old boy began hearing voices coming from the walls and the school intercom telling him to hurt himself and others. He saw ghosts, aliens in trees, and colored footprints. Joseph Gonzalez-Heydrich, MD, a psychiatrist at Boston Children’s Hospital, put him on antipsychotic medications and the frightening hallucinations stopped. Another child, at age 4, had hallucinations with monsters, a big black wolf, spiders, and a man with blood on his face.
While children are known for their active imaginations, it’s extremely rare for them to have true psychotic symptoms. Through chromosomal array testing, both children were found to have copy number variants or CNVs, meaning deletions of duplications of chunks of their DNA.
More here.