What is premorbid intelligence?

Premorbid intelligence refers to an individual's cognitive functioning or intellectual ability prior to the onset of a medical condition, such as a neurological disorder or mental illness. It serves as a baseline for assessing changes in cognitive performance over time, particularly after an injury or illness. Understanding premorbid intelligence can help clinicians differentiate between normal age-related decline and impairment due to specific conditions. This concept is often evaluated through standardized tests or estimations based on educational and occupational history.