What is considered the first known surgical procedure believed to cure mental illness?

Trephenation is recognized as one of the earliest surgical procedures believed to address mental illness, dating back to prehistoric times. This procedure involved drilling or scraping a hole into the human skull to purportedly release evil spirits or alleviate pressure from the brain, which was thought to be the cause of various mental health conditions. The practice was rooted in ancient beliefs about the connections between physical and mental health, illustrating an early understanding, albeit rudimentary, of the brain's role in behavior and cognition.

In contrast, lobotomy is a much later development in surgical psychiatry, emerging in the 20th century, specifically designed to treat severe mental disorders, but carried significant ethical and health implications. Electroconvulsive therapy, developed in the 1930s, became a recognized treatment for severe depression and certain other mental illnesses, but it is not the earliest known procedure. Exorcism, on the other hand, is more rooted in spiritual and religious practices rather than surgical intervention, reflecting cultural approaches to mental illness rather than medical ones. Thus, trephenation stands out as the first known surgical attempt to "cure" issues associated with mental illness.