According to the DSM-5, the diagnosis of schizophrenia requires both of the following: ≥ 2 characteristic symptoms (delusions, hallucinations, disorganized speech, disorganized behavior, negative symptoms) for a significant portion of a 6-month period (symptoms must include at least one of the first 3) Prodromal or attenuated signs of illness with social, occupational, or self-care impairments evident for a 6-month period that includes 1 month of active symptoms Differential diagnosis Psychosis due to other medical disorders or to substance use disorders must be ruled out by history and examination that includes laboratory tests and neuroimaging (Medical Assessment of the Patient With Mental Symptoms).