What is the minimum number of symptoms required for a schizophrenia diagnosis?

To diagnose schizophrenia, a minimum of two symptoms from a specific set must be present during a significant part of a one-month period. These symptoms include delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms. This criterion is established in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which outlines that having at least two of these symptoms is necessary for a formal diagnosis.

Having only one symptom may indicate other conditions or a less severe form of mental health disorder, but it does not meet the threshold for schizophrenia. Therefore, the requirement of two symptoms serves as a standard to ensure that the diagnosis reflects a more comprehensive and significant impairment in functioning associated with the disorder.