The Interface Between Religion and Psychosis

PSYCHIATRY AND RELIGION

The evolution of psychiatry has historically been shaped by its contemporary sociocultural milieu. Religion, being a primary constituent of culture, has had a particularly influential role in the conceptualization of illness. This is exemplified by medieval demonic possession explanatory models for epilepsy and mental illness.[2] Indeed, such beliefs of demonic causality remain current, as illustrated by a study that reported their prevalence in both psychotic disorders (56% of the sample with schizophrenia) and non-psychotic disorders (29% in affective, 48% in anxiety, 37% in personality and 23% in adjustment disorders), in a self-described religious cohort.[3] Apart from these links, there are more subtle forms of religious influences, as illustrated by the notion of religious meanings, such as ‘retribution’ or ‘spiritual challenge’, for illness.

Religion has also been argued to be a manifestation of unsound psychological processes.[4–9] Freud, in his extensive writings on religion that evolved over several decades, variously considered it a collective social mechanism to process the Oedipal complex,[5] an illusion and neurosis that could be overcome through maturation,[7] and mass-delusion or a psychotic defence against reality.[6] Ellis has also strongly asserted the irrational basis of religion, which he equated with psychopathology.[4]

Others have expressed more temperate views on the psychology of religion. Among these, the works of William James have been widely regarded as the defining literature of the field. In his classic work from 1902, The Varieties of Religious Experience,[10] James made the distinction between institutional and personal religion. He considered the latter, referring to personal mystical or religious experiences, to be more primordial and of greater interest in the understanding of religious experiences than institutional or organized religion, which he conceptualized as the culture stemming from such personal experiences. Further, he connected these remarkable personal experiences with ‘nervous instability’ or abnormal psychological processes. These ideas, laid down over a century ago, are foundations for the modern delineation between religion as a culture and religiosity as pathology. It is this pathological aspect, and not the abstract social concept of religion, that will be the focus of further discussion.

MANIFESTATIONS OF RELIGIOUS THEMES IN PSYCHOSIS

Religious trances, glossolalia and spontaneous acute religious psychosis such as the Jerusalem Syndrome, all conjure up mystical imageries and attract both spiritual and psychopathological explanations.[11], [12] The Jerusalem Syndrome was coined to describe an acute psychotic state seen in tourists visiting the city. A discrete subtype of this syndrome, occurring in those without previous signs of mental illness, is marked by a characteristic progression of events from nervous excitement to the delivery of a sermon at a religious site, and is proposed to be induced by the religious excitement associated with the holy city.[11] Such dramatic encounters are rare in clinical practice, and most religious psychotic phenomena is demonstrated by patients with schizophrenia or affective psychoses. The prevalence estimates are unclear, but one cross-sectional study reported religious delusions in 24% of hospitalized patients with schizophrenia.[13]

Over the course of time, religion has been identified as one of few enduring psychotic themes that have been observed across cultures.[14] Persecution, grandiosity, guilt, hypochondria, jealousy and love complete the list. These themes all hold unique anthropological salience for the organization of human relationships.[14] However, while delusions of persecution and grandiosity have been the most frequent and stable over time, religious delusions have shown longitudinal variations and have become less frequent over the course of the last century.[15] This has most likely been influenced by changes in societal values and a shift towards a more secular world.

The boundary between ‘normal’ religious beliefs and psychosis can be indistinct, and the benefit of conceptualizing these as existing on a continuum has often been emphasized.[9], [16], [17] Similarities have been observed between schizotypal religious beliefs and psychosis. These may be difficult to differentiate in terms of delusional measures including level of conviction, although those with schizotypy have fared better in functional measures than those with psychosis,[16] which again lends strength to a spectral conceptualization of these disorders.

Another angle of study has explored the relationship between religious affiliation and the development of psychosis. The few studies that have examined this have been inconclusive, with some suggestion of increased frequency, but not severity, of religious delusions in certain religious groups.[16], [18], [19] Even without these inconsistent findings, the specific role of religious affiliation in the complex genesis of psychosis would be difficult to ascertain.

THE BIOLOGICAL SUBSTRATES OF RELIGIOUS EXPERIENCES

James had contended that specific religious emotions did not exist but, rather, personal religious experiences were merely regular emotions interpreted in religious contexts. He described four characteristics of mystical experience, which were ineffability, noetic quality, transiency and passivity.[10] In a modern expansion of these ideas, Saver and Rabin argued that religious and non-religious experiences shared common neural substrates, only that religious experiences were generated by the superimposition of numinous–mystical perceptions on ordinary sensations.[20] By examining religious phenomena in epilepsy, near-death experiences, hallucinogen effects, psychotic disorders and dementias, they put forth the limbic marker hypothesis to explain the occurrence of religious and mystical experiences. They postulated that the limbic system, in its crucial role of attaching affective valence to events, could produce states of discrepant affects and cognitions. These include perceptions of excessive importance or self-reference, harmonious and noetic feelings, and profound joy, all of which have frequently been reported in religious and mystical phenomena. Furthermore, the authors proposed that the ineffability of religious experiences could arise from the discrepancies between the high affective valence tagged onto such experiences and the ordinariness of their perceptual and cognitive contents. However, this hypothesis can at best only partially account for the development of religious psychotic phenomena, as the interpretation of perceptual and affective experiences must involve the intricate interplay of innumerable neural pathways, which in themselves would have been shaped by myriad neurogenic and environmental variables. The incompleteness of this otherwise instructive hypothesis is attested by the apsychotic state of many patients with temporolimbic dysfunction.

In alignment with the limbic marker hypothesis, there is evidence from different sources of investigations to support temporolimbic overactivity as an underlying process in religious psychotic phenomena. The association between temporal lobe epilepsy and religious or paranormal experiences has long been recognized.[20–22] Dysfunctional mesolimbic activities, in particular in the hippocampus and amygdala, can produce altered perceptions of reality, such as distorted sense of time (timelessness), ego boundary (autoscopy, depersonalization), external reality (derealization), and familiarity (déjà vu, jamais vu).[20], [21], [23] Direct stimulation of these structures has been able to evoke similar events, and enhance the vividness of perceptions.[21] Persinger and colleagues reported the evocation of a ‘sentient presence’, haunted experience and distortions in subjective time by transcranial magnetic field manipulations over the temporal lobe.[24], [25] This claim has been questioned, especially the generalizability of experimental findings to ambient magnetic fields and the confounding role of the suggestibility factor.[26] In the first functional neuroimaging study of religious delusions in schizophrenia, Puri et al. found an association between religious delusions and left temporal overactivation/left occipital underactivity.[27]

HYPOTHESIS OF RELIGIOUS PSYCHOTIC SYMPTOM FORMATION

Maher has proposed that delusions arise from normal interpretations of abnormal experiences.[9], [28] This argument is supported by Saver and Rabin's limbic marker hypothesis[20] and Persinger's concept of amygdaloid lability, proposed to explain the emergence of a deeply personal paranormal experience as the result of enhanced meaning attached to mundane perceptual events through labile amygdaloid processes.[21] While a plausible theory that fits with the rudimentary and inferential neurological evidence already outlined, this theory only partially explains the evolution of religious psychotic phenomena.

All psychotic syndromes must have an underlying neurocognitive basis, but the foci of dysfunction are likely to be as diverse as the neurocognitive networks are complex. It is more likely that psychosis may arise from both abnormal perceptual experiences and abnormal interpretation of normal experiences, although the relative contribution of each may vary. However, it is possible that a higher proportion of perceptual abnormalities is captured in those with religiously themed psychotic phenomena. Importantly, all beliefs, whether deemed to lie within or outside the realms of reality, are permeated with personal history and sociocultural values. In trying to make sense of discrepant perceptual events, the eventual conclusions must be shaped by individual and cultural frameworks. Given the ubiquity of the major religious frameworks, it is perhaps not surprising that unusual perceptions are commonly interpreted as divine experiences. This cultural factor may be relevant in the variable prevalence of religious delusions over the course of history,[15] and the observation by Getz and colleagues of increased frequency of religious delusions in Protestant patients with psychosis.[19]

CLINICAL IMPLICATIONS

Clinicians have inherent biases where religious interpretations are required. It has been reported that far fewer psychiatrists in the United States believe in God than the general population.[9] This has been referred to as ‘the religiosity gap’.[29], [30] Furthermore, selection and education of psychiatrists encourage a natural predilection for scientific and illness explanations, even though psychiatric training teaches the importance of a holistic approach in all aspects of clinical practice. Therefore, psychiatrists in general are probably not well placed to assess religious and spiritual beliefs, especially those outside the mainstream. However, psychiatrists are expertly placed to assess for the presence of mental illness. These two issues can potentially be confused with one another, and it may be helpful to remain focused on the core questions that one needs to answer in order to make an accurate diagnosis.

The current major psychiatric diagnostic classifications such as the DSM-IV-TR have been criticized for offering no specific guidelines on the assessment of religious beliefs.[9], [17], [30] This likely reflects the nuanced definitions of normality and pathology, and the inadequacies of a syndromal categorization of mental illness. Investigation into mental health professionals’ assessment of the pathognomonic significance of religious beliefs has suggested inconsistencies in clinical judgement, with deviation from familiar religions and risk of harm identified as factors determining the degree of pathology, rather than dimensions of the religious experiences themselves.[17], [30]

Regardless of the instructiveness of psychiatric diagnostic classifications, clinical judgement remains the primary diagnostic tool for challenging phenomenology. It is useful for clinicians to remain vigilant to the fact that normality and illness are culturally defined, and to recognize their own limitations in theological knowledge. Seeking education of unfamiliar religious beliefs and practices, and deliberating the dimensional characteristics of possible delusional beliefs (i.e. degree of preoccupation, conviction, emotional valence, functional impairment) are recommended.[9] Ultimately, diagnosis hinges on the presence of disturbed neurocognitive functioning, and it is these features, such as symptoms of temporolimbic overactivity and higher information processing dysfunction, that should be actively sought in clinical assessment.

CONCLUSIONS

Psychosis is fundamentally a neuropathological disorder involving aberrant reception and/or processing of information. Phenotypically, these disturbances can manifest in different ways. Religion is a common theme, possibly due to its intrinsic and cultural significance to humans, and the natural interpretation of intense or discrepant perceptual events as spiritual or paranormal. There is evidence to implicate temporolimbic dysfunction in the pathogenesis of psychosis, which is perhaps more likely to generate the type of perceptual experiences that resemble paranormal or spiritual events. However, this does not argue against the essence of religious beliefs, but rather suggests that some neuropathological processes can simulate religious experiences. Clinically, the challenge lies in the differentiation between religious culture and pathology, and this requires a thorough assessment of the dimensions of beliefs as well as minimizing any premature judgements based on ignorance of unfamiliar religions.