For schizophrenia, how many symptoms must be present for diagnosis?

For a diagnosis of schizophrenia, the criterion requires the presence of at least two of the following symptoms: delusions, hallucinations, disorganized thinking (speech), grossly disorganized or abnormal motor behavior (including catatonia), and negative symptoms (such as diminished emotional expression or lack of motivation). These symptoms must significantly impair the individual’s functioning and persist for a considerable duration, typically for at least six months, with at least one month of active symptoms. Therefore, the requirement of having two symptoms underscores the need for a clear and consistent presence of these behaviors to make a reliable diagnosis of the disorder. This ensures that the diagnosis captures the complexity and varied manifestations of schizophrenia, distinguishing it from other mental health issues.