What Two Psychiatrists Saw at Exorcisms, and What It Means for Catholic Clinical Care

Two psychiatrists studying possession from opposite sides of the Atlantic and decades apart reached strikingly similar numbers. José Miguel Gaona, a Spanish forensic neuropsychiatrist whose recent 1,000-page book Possession grew out of five years spent observing exorcisms (including time learning from Father Gabriele Amorth), puts psychiatry's share of cases at 95 to 97 percent, with 3 to 5 percent resisting any established diagnosis.[^1] Richard Gallagher, a Princeton- and Yale-trained psychiatrist who teaches at New York Medical College and Columbia, spent twenty-five years reaching a comparable conclusion after directly observing roughly a hundred exorcisms of his own.[^2] Neither claims this proves anything in a scientific sense; both frame their work as a question about where materialism's explanatory reach actually ends, standing squarely inside science rather than against it.

Diagnosing possession is not the clinician's job

The Church has never asked psychiatrists to rule on whether a case is demonic. Canon law permits only priests with a bishop's explicit authorization to perform an exorcism, and the Church's own 1999 rite requires that a person believed to be possessed first undergo a psychiatric or medical evaluation ruling out natural causes.[^3] The Catholic Psychotherapy Association's own practice guidelines for clinicians spell out where that boundary actually sits: a psychiatrist's job stops at the medical and psychological picture, ruling conditions in or out and judging whether they fully explain what's happening. Whether any of it is genuinely demonic is a determination the guidelines explicitly leave to the Church, not the clinician.[^4]

What a real work-up looks like

In interviews describing his own process, Gallagher has said he runs a full medical work-up first, checking for things like an undiagnosed seizure disorder or brain injury that could explain the symptoms, and separately talks to people close to the patient to see whether their account holds up independently.[^5] A possible possession case, on this premise, deserves exactly the same diagnostic rigor as any other unusual psychiatric presentation. A full differential has to seriously weigh dissociative disorders, psychotic-spectrum conditions, trauma-related presentations, and personality disorders capable of producing altered states or an apparent loss of control, all before any conversation about spiritual causation begins.

The traditional signs a priest looks for when discerning a case, drawn from the Rituale Romanum: speaking or understanding a language never learned, knowledge of hidden or distant things, physical strength beyond what the person's frame should allow, and a marked aversion to the sacred.[^6] A priest weighs these when discerning whether to proceed with the rite. A clinician's task runs the opposite direction: asking whether a dissociative process could account for the same behavior instead. The DSM classifies experiences described as possession as a culturally patterned form of dissociation, most recently as a variant within dissociative identity disorder, which is itself the standard first differential a clinician should work through before concluding that a presentation resists ordinary explanation.[^7]

Building the exorcist a real clinical picture matters as much as ruling conditions out: history, attachment patterns, trauma exposure, and current functioning are material a priest has no way to gather on his own, and a clinician who stays present through what can be a months-long process offers something the rite itself doesn't: a full review of the person's natural psychological life and family history.

Consultation runs both directions

In practice, referral runs both ways: a clinician can send a case to their diocese for evaluation, and clergy just as often send someone to a mental health professional first, or instead of proceeding with the rite at all.[^4] Luigi Janiri, who directs psychiatry at Rome's Gemelli Hospital and has spent years working alongside exorcists, put the underlying logic simply: building real competence into both disciplines matters more than picking a side between psychiatry and exorcism, so a psychiatrist can recognize the point where a case genuinely exceeds ordinary explanation, and an exorcist has enough grounding in psychopathology to send someone to a doctor instead of proceeding with a rite they don't actually need.[^1]

None of this resolves whether Gaona's or Gallagher's small remainder is genuinely inexplicable. What it does is close a gap that matters more in daily clinical practice than that question does: a Catholic clinician who takes a client's fear of possession seriously has concrete, non-speculative work to do first, and a real structure, not guesswork, for deciding when that work is finished and someone else's competence should take over.

References

[^1]: Asturias, C. (2026, July 22). When Psychiatry Faces the Inexplicable. Two Doctors Delve Into Exorcisms; Both Confirm What the Church Says: The Devil Exists. ZENIT News. [^2]: Gallagher, R. (2020). Demonic Foes: My Twenty-Five Years as a Psychiatrist Investigating Possessions, Diabolical Attacks, and the Paranormal. HarperCollins. [^3]: Code of Canon Law (1983), canon 1172; Congregation for Divine Worship and the Discipline of the Sacraments, De Exorcismis et Supplicationibus Quibusdam (1999 typical edition). [^4]: Catholic Psychotherapy Association, Deliverance & Exorcism Ministry Special Interest Group, Guidelines for Mental Health Professionals Supporting Persons Seeking Freedom from Possession and Other Spiritual Afflictions (2nd ed.). [^5]: Tomlinson, H. (2024, October 7). The Mainstream Psychiatrist Who Confirms Demonic Possession Is Real. Christian Today. (Quotes Gallagher's account of his diagnostic method, itself drawn from an earlier interview he gave the Daily Mail.) [^6]: Rituale Romanum (1614; revised 1999). [^7]: American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev., 2022), dissociative identity disorder criteria and associated cultural note on possession-form presentations.