A 15-year-old boy is brought by his father to the psychiatric mental health nurse practitioner (PMHNP) for evaluation of what he considers unusual behavior. The boy's father states that for the past 2 months, his son claims he can communicate with "aliens from another planet." During this same time, he has been withdrawn from friends and activities, and he has been less talkative at home, making it difficult to communicate with him. What is the most likely diagnosis?

Choice A reason: Schizophrenia requires symptoms to persist for at least six months, including at least one month of active-phase symptoms such as delusions, hallucinations, or disorganized speech. Since the boy’s symptoms have lasted only two months, this diagnosis is premature. Choice B reason: Brief psychotic disorder involves sudden onset of psychotic symptoms lasting more than one day but less than one month, followed by full recovery. The boy’s symptoms have persisted for two months, which exceeds the duration criteria for this diagnosis. Choice C reason: Schizoaffective disorder includes symptoms of schizophrenia along with prominent mood episodes (either depressive or manic). There is no mention of mood symptoms in this case, making schizoaffective disorder unlikely. Choice D reason: Schizophreniform disorder is diagnosed when symptoms of schizophrenia are present for more than one month but less than six months. The boy’s delusions, social withdrawal, and communication difficulties over two months fit this timeframe, making this the most appropriate diagnosis.