What are the four levels of mental retardation?

The four grades of mental retardation are mild, moderate, severe and extremely severe. These four grades are mainly evaluated and classified according to the patient's IQ level, adaptability, learning ability and social function, so as to formulate corresponding rehabilitation plans and intervention measures to help patients improve their self-care ability and social adaptability as much as possible.

For specific grading standards and related treatment methods of mental retardation, it is recommended to consult professional medical institutions or psychiatrists to provide more detailed and accurate evaluation and suggestions according to the specific conditions of patients.