A 15-year-old young man lived with his mother and did relatively well until he was found smoking marijuana and was suspended from school. He attended another school and did well for 1 year until his grades started to fall. Over the following few months, he began to feel unmotivated and to began to isolate himself. There was no history of suicidal ideation, feeling of guilt or hopelessness, or sleep or appetite disturbances. He was seen by a psychiatrist, who prescribed bupropion 150 mg daily for what appeared to be depression. One week later, his mother found him in the basement holding a bat in his hand and stating that he wanted to protect himself from unseen harm. He was brought to ER, where organic causes were excluded. His physical and neurological examinations were unremarkable. His laboratory tests were within normal limits. CT head revealed no pathology, and urine toxicology was negative. He denied any medical condition and recent drug abuse. Reportedly, the patient abused marijuana only for a few times 1 year before his admission. There was no past or family history of psychiatric illness and no concomitant use of medications. The patient was admitted for psychiatric evaluation. Initially, he was electively mute, socially withdrawn, and suspicious. He believed that he was being controlled by a destructive force and he is on a mission to protect the world. He was neglecting his personal hygiene and eating poorly; he then became catatonic. He did not report any perceptual disturbances, manic symptoms, or suicidal ideation. Bupropion was stopped, but he patient remained symptomatic. He was stabilized on olanzapine 25 mg daily. His delusions were successfully remitted. His social interaction, oral intake, and personal hygiene improved. Three months later, olanzapine was stopped because of side effects; subsequently, the patient decompensated and was rehospitalized.