Ramu, a 22 year old single unmarried man is suffering from the sudden onset of 3rd person hallucination for the past 2 weeks. He is suspicious of his family members and had decreased sleep and appetite. The diagnosis is -
This patient has :-

Third person hallucinations
Delusions of persecution (suspicious about family members)
Negative symptoms (decreased sleep & appetite)

More than 2 characteristic criteria are present. However the symptoms are present only for 2 weeks :-

Typical symptoms of schizophrenia for → 6 months schizophrenia.
Typical symptoms of schizophrenia for 1-6 months → schizophreniform disorders.

Typical symptoms of schizophrenia for less than 1 months → Acute schizophrenia-like psychotic disorder (brief psychotic disorder).
Schizophrenia
Acute Psychosis
Acute mania
Acute delirium