Ancient Beliefs About Mental Illness: From Demons to Trephination

Long before brain scans, talk therapy, or psychiatric medication existed, people still experienced what we now call mental illness. Hallucinations, mood swings, seizures, and disordered thinking were not new to the modern world; they have been part of the human experience for thousands of years. What changed dramatically over time was the explanation. Ancient societies, lacking the tools of neuroscience, looked toward the invisible world for answers. They saw mental illness as the work of demons, displeased gods, or wandering spirits, and they developed treatments that, by today’s standards, range from the strange to the genuinely disturbing.

A world ruled by spirits 🔗

In most ancient civilisations, the boundary between the physical and the spiritual was thin and porous. If a crop failed, a god was angry. If a storm hit, a deity was at war. So when a person began behaving in ways that no one could explain, the same logic applied: something unseen had taken hold of them. According to a historical review of mental illness, supernatural theories attributing abnormal behaviour to possession by evil spirits, displeasure of gods, eclipses, curses, and sin dominated human thinking for most of recorded history.

This was not a sign of backwardness. It was the most coherent explanation available in a world without microscopes, neurology, or psychology. If someone heard voices no one else could hear or fell into sudden convulsions, the conclusion was almost universal across cultures: an outside force had invaded the body.

Mesopotamia and the hand of the gods 🔗

Some of the earliest written records of mental illness come from ancient Mesopotamia, where city-states like Babylon and Ur thrived along the Tigris and Euphrates. Clay tablets dating back roughly 4,000 years describe conditions we might today recognise as epilepsy, psychosis, or depression. Mesopotamian healers developed an elaborate system in which different deities and demons were responsible for different ailments, leading to conditions named “Hand of Ishtar” or “Hand of the Ghost.” Specialised exorcist-healers called Ashipu maintained diagnostic manuals identifying which supernatural entity caused which symptom and the proper ritual to respond.

Egypt, Greece, and the early supernatural framework 🔗

In ancient Egypt, mental disturbances were viewed as spiritual imbalances rather than brain disorders. Priests acted as intermediaries between the divine and mortal worlds, performing rituals, prescribing amulets, and combining prayers with herbal preparations. The Hebrews, meanwhile, often saw madness as a punishment from God, with confession and repentance considered part of the cure.

Even in classical antiquity, despite occasional flashes of naturalistic thinking, supernatural explanations persisted. As one academic source notes, throughout classical antiquity there was a return to supernatural theories of demonic possession or godly displeasure to account for abnormal behaviour, with temple ceremonies and incantations forming a major part of treatment.

Echoes in ancient India 🔗

The subcontinent had its own version of this supernatural framework. Mental disorders were frequently linked to sorcery, witchcraft, and the displeasure of spiritual forces. Texts like the Ramayana and Mahabharata describe states resembling severe depression and anxiety. Even the Charaka Samhita, a foundational Ayurvedic text that introduced the more medical idea of imbalances among three bodily forces, still listed causes such as disrespect toward gods and mental shocks from intense fear. The supernatural and the medical were not separate worlds; they were two sides of the same coin.

Trephination: drilling a hole to let the spirits out 🔗

If mental illness was caused by a spirit trapped inside the body, then it followed, in ancient logic, that the spirit needed a way out. This belief gave rise to one of the most striking medical practices in human history: trephination, also called trepanning or burr holing.

Trephination is a procedure in which a hole is drilled, scraped, or cut into the human skull using simple surgical tools. It is widely considered the oldest surgical procedure for which archaeological evidence exists. According to historical records, the technique was used to treat intracranial diseases, epileptic seizures, migraines, and mental disorders by relieving pressure, and also as a primitive form of emergency surgery to remove shattered pieces of bone from skull fractures.

How old is this practice? 🔗

Astonishingly old. Skulls bearing the marks of deliberate trephination have been found across Europe, Asia, Africa, Oceania, and the Americas, dating as far back as the Neolithic period. Examination of prehistoric skulls and cave art from as early as 6500 BC has identified surgical drilling of holes in skulls to treat head injuries, epilepsy, and mental disorders, with the explicit aim of releasing evil spirits trapped within.

The subcontinent is part of this story too. Archaeological evidence shows that trephination was practised on the Indian subcontinent during the Bronze Age, with one well-known find being the skull of a young child bearing a square hole at Lothal, a site associated with the Indus Valley Civilisation.

How it was done 🔗

The instruments evolved over time. Early practitioners used sharpened flint, obsidian, or other hard stone tools. As metallurgy advanced, bronze and copper instruments replaced stone. Researchers have identified five distinct methods of trephination across centuries: scraping, bore and saw, sawing, drilling, and gouging, each varying in how much bone was removed.

What’s remarkable is that many patients survived. Healed bone around the hole on excavated skulls suggests the procedure was often non-fatal, and in documented twentieth-century cases of trepanning in parts of Africa and Oceania, survival rates approached 90 percent. The removed piece of bone was often kept by the patient or family, sometimes worn as an amulet to ward off further evil spirits.

A surprisingly long shelf life 🔗

Trephination did not vanish with the ancient world. The Greek physician Hippocrates recommended the procedure to drain blood after cranial injury. The Roman surgeon Galen later refined the technique and discussed its effects on intracranial pressure. According to medical historians, a thirteenth-century surgical text recommended opening the skulls of epileptics so that bad humours and air could evaporate out. The practice continued, in various forms, well into the 1800s as a treatment for epilepsy and mental illness in parts of Europe.

Exorcism: casting out the demons 🔗

While trephination targeted the body as a container, exorcism targeted the spirits themselves. The idea was straightforward: if a demon had entered, it could be commanded, frightened, or driven out. This belief produced a vast catalogue of rituals across cultures, some gentle and prayerful, others extraordinarily harsh.

Early Greek, Hebrew, Egyptian, and Chinese cultures used exorcism as a method to cast out evil spirits through prayer, magic, flogging, starvation, noise-making, or having the person ingest horrible-tasting drinks. The reasoning was that the body could be made so inhospitable that any possessing entity would prefer to leave.

The Babylonian Ashipu and ritual healing 🔗

In Mesopotamia, exorcism was a highly organised profession. The Ashipu were trained specialists who diagnosed which specific demon or god was responsible for a person’s affliction and prescribed a tailored ritual. Treatments included incantations, offerings, symbolic substitutions, and prayers. There was a kind of bureaucracy to the supernatural, with each entity demanding its own protocol.

Beyond prayer: the harsh side of exorcism 🔗

Not every exorcism involved only words and rituals. When prayers and incantations failed to produce results, many cultures turned to far more physically punishing interventions, all based on the same logic: make the host body unattractive to the demon.

Corporal punishment: Whipping, flogging, and beating were used in the belief that physical pain would drive possessing spirits out. This continued well into the medieval period, when treatment of mental illness was primarily left to the clergy who exorcised patients through techniques that caused physical pain, such as scourging.

Starvation and dehydration: Denying food and water was thought to weaken the demon while leaving the human host alive long enough to recover. Tragically, this approach has occasionally surfaced even in modern attempts at exorcism, with documented cases of death due to prolonged deprivation.

Shock interventions: Sudden immersion in cold water, loud noise-making, and exposure to disturbing stimuli were used in attempts to startle the spirit out of the body. The principle was crude shock therapy, centuries before any neurological understanding existed.

Foul substances and induced vomiting: Patients were sometimes forced to drink bitter, foul-smelling concoctions or made to vomit repeatedly, both as a way of expelling impurity and as a deterrent to the lurking entity.

Why these treatments persisted 🔗

From a modern viewpoint, it is easy to dismiss these practices as cruel or absurd. But they followed an internal logic that made sense within the worldview of the time. If you genuinely believed a demon was inside someone, then making the body uncomfortable for that demon was a humane act, intended to save the patient. The cruelty, in many cases, was not the goal; it was the unintended consequence of a wrong theory pursued sincerely.

These beliefs also persisted because, occasionally, patients did improve. Spontaneous recovery from mental health episodes is common, and any improvement was credited to the ritual. This created a powerful feedback loop that kept supernatural explanations alive for thousands of years.

The slow shift toward natural explanations 🔗

The first major break from this framework came with the Greek physician Hippocrates around 400 BCE. He proposed that mental disorders were akin to physical disorders and had natural causes, linking them to imbalances among four bodily fluids called humours. The theory was wrong in its details, but it was revolutionary in spirit. For the first time, mental illness was being placed inside the body rather than the spirit world.

Still, the shift was slow and uneven. Supernatural explanations roared back during the Middle Ages, and even today, traces of these older frameworks remain in many cultures, where spiritual healing and modern psychiatric care often coexist.

Lessons from ancient beliefs 🔗

Looking back at trephination, exorcism, and the brutal physical treatments of antiquity, the temptation is to feel superior. Yet the history carries a quieter lesson. People in every era have done their best to explain suffering using the tools and beliefs available to them. The story of mental illness is, in many ways, the story of how humans have repeatedly tried to make sense of pain they could not see.

Modern psychiatry, neuroscience, and psychology have replaced demons with neurotransmitters and rituals with evidence-based therapy. But stigma, fear, and misunderstanding around mental illness have not fully disappeared. Recognising where these attitudes came from helps us understand why mental health still carries so much cultural weight today.

What do you think? If ancient peoples were doing their best with the knowledge they had, what current mental health practices might future generations look back on with the same mix of curiosity and concern? And how much of the supernatural framing of mental illness still lingers, quietly, in the way we talk about it today?

References

1. https://nobaproject.com/modules/history-of-mental-illness
2. https://www.ukatlondonclinic.com/blog/mental-health/demons-and-mental-illness-in-ancient-mesopotamia/
3. https://www.worldhistory.org/Trephination/
4. https://courses.lumenlearning.com/wm-abnormalpsych/chapter/mental-health-treatment-past-and-present/
5. https://codmansurgical.integralife.com/trephinations-to-craniotomies-early-innovations-in-neurosurgery/
6. https://thereader.mitpress.mit.edu/hole-in-the-head-trepanation/
7. https://www.saskoer.ca/abnormalpsychology/chapter/part-2/
8. https://www.ancient-origins.net/news-mysterious-phenomena-unexplained-phenomena/ancient-practice-exorcism-rise-again-001211
9. https://psychology.town/fundamentals-of-mental-health/mental-illness-middle-ages-supernatural-beliefs/
10. https://courses.lumenlearning.com/hvcc-abnormalpsychology/chapter/1-5-prominent-themes-in-abnormal-psychology-throughout-history/