Schizophrenia requires continuous signs of disturbance for at least how long?

• A. 1 month
• B. 3 months
• C. 6 months
• D. 12 months

Answer: (C)

The duration criterion is what this item tests. For a schizophrenia diagnosis, there must be continuous signs of disturbance for at least six months. That six-month period can include prodromal or residual symptoms, as long as there is at least one month of active-phase symptoms such as delusions, hallucinations, disorganized speech, disorganized or catatonic behavior, or negative symptoms. This minimum six-month requirement helps distinguish schizophrenia from shorter-duration psychotic disorders like brief psychotic disorder (less than one month) and schizophreniform disorder (one to six months). While symptoms can extend beyond six months, the key point is that the disturbance must persist for a minimum of six months.