Epilepsy was associated with behavioral changes and religious fervor since the time of Hippocrates. Since these ancient times, seizures were thought to be due to demonic or divine influences.
From the initial descriptions of personality changes, Gowers, Gibbs, and later Gastaut all described cognitive, memory, behavioral, and psychiatric changes in patients with epilepsy, in particular temporal lobe epilepsy (TLE).
Hyperreligiosity in epilepsy has been known to be part of the Gastaut-Geshwind syndrome which also consists of hypergraphia (Hypergraphia is a behavioral condition characterized by the intense desire to write or draw. Forms of hypergraphia can vary in writing style and content. It is a symptom associated with temporal lobe changes in epilepsy and in Geschwind syndrome) or excessive compulsive writing, altered sexual behavior, aggression, stickiness or viscosity, preoccupation with details, seriousness, and circumstantiality.
Hyperreligiosity may be an ictal (during seizures), an interictal (in between seizures), or a postictal (after seizures) phenomenology. Ictal religiosity is a type of ecstatic seizure, such as feelings of joy or pleasure. Different examples of ictal religious experiences include intense emotions of God’s presence, hallucinations of God’s voice, clairvoyance, or even telepathy. A religious aura for hours or days preceding ictal events in epileptics was also described. Postictal hyperreligiosity is usually manifested as prolonged intense religiosity lasting hours to days; multiple reports have been published in which subjects had religious conversions after having a seizure. Interictal religiosity presents as a heightened state of religious conviction with personality changes.
A handful of large studies provide better characterization of these events. In 1989, Roberts and Guberman showed in a study of 50 patients with temporal lobe epilepsy that 51 percent of these patients had an experience of salvation. In a study of 234 patients, 1.3 percent had ictal (during seizures) religious experiences, usually associated with right temporal lobe origin. Experiences included a sense of presence of God and auditory or visual hallucinations of God. A more recent study in 2014 showed that self-reported spirituality scores were higher not only in patients with temporal lobe epilepsy but also in epileptics with lower education level which may influence their response to these epileptic spiritual events.
The pathophysiology of hyperreligiosity is complex and not fully understood. Religiosity in epilepsy is thought to originate in the limbic system due to its association with the temporal lobe and its function in emotions. Kindling, which refers to an enhancement of seizure susceptibility due to repeated stimulation, might be one of the ways hyperreligiosity develops as it is believed activation and strengthening of limbic-cortical connections occur in these patients.
Chronic stimulation of the amygdala due to seizure activity may lead to altered behavior and heightened emotionality during the interictal period. This behavior is what is known as epileptic personality or interictal behavior. Geshwind described this as the interictal behavioral syndrome, which he observed in subjects with temporal lobe epilepsy who had a chronic change in personality which became more striking as time passes. Postictal religiosity may be associated with bilateral temporal lobe dysfunction or a bilateral expression of a postictal state due to single focus. This bilateral association was also described in postictal psychosis.
Hyperreligiosity and psychosis are less common behavioral manifestations in epilepsy. Other more common behavioral changes include depression, anxiety, agitation, aggression, hyperactivity, inattention, attention deficit hyperactive disorder, and mood liability; up to 75% of patients with epilepsy have some behavioral comorbidities.
Hyperreligiosity is a known epileptic manifestation that may be an ictal, interictal, or postictal phenomenon, requiring appropriate diagnosis and treatment to prevent further neurologic injury.
Garcia-Santibanez R, Sarva H. Isolated Hyperreligiosity in a Patient with Temporal Lobe Epilepsy. Case Rep Neurol Med. 2015;2015:235856. doi: 10.1155/2015/235856. Epub 2015 Aug 13. PMID: 26351599; PMCID: PMC4550801.