The objective of this randomized controlled trial (RCT) is to compare the changes of the sleep-related memory functions in patients with psychosis after they have completed the 12-week high-intensity exercise intervention, the 12-week low-intensity exercise intervention, or the 12-week controlled non-exercise intervention respectively. Fifty-one patients with psychosis, patients who received either the high-intensity exercise or low-intensity exercise as intervention shown a significant improvement to their impaired sleep-related memory function, while those who received non-exercise intervention has no such improvement. Moreover, high-intensity exercise may have a more prominent effect compare to low-intensity exercise.

Inclusion Criteria:

• Aged from 18 to 55
• Based on the SCID diagnosed to have schizophrenia and related psychotic disorders
• Ability to understand the nature of the study and to give written informed consent

Exclusion Criteria:

• Severe physical illness (Myocardial Infarction, Hypertension, Fracture, Spinal problems in which exercise may be contraindicated), and seizure disorders
• Comorbid substance dependence
• Unstable psychotic symptoms
• A history of brain trauma or organic brain disease
• Known history of intellectual disability or special school attendance
• Answered one or more "yes" in the PAR-Q and without doctors approval for exercise