Jill remains motionless in a single posture for extended durations, showing signs of muscle stiffness. Which condition is Jill most likely experiencing?

Explanation

The symptom of maintaining a fixed posture with muscular rigidity is characteristic of catatonic schizophrenia. This subtype involves motor disturbances such as stupor, rigidity, or excessive movement, distinguishing it from other forms like hebephrenic, undifferentiated, or paranoid schizophrenia.