Psychiatry
Research Is Shedding New Light on Hearing Voices
Hearing voices can have little—or life-changing significance.
Posted March 19, 2018
What are we to think of someone who says that God has spoken to them? Often the expression “speaks to me” is used figuratively, not literally. When something really speaks to you, you mean that it is meaningful and emotionally relevant to you. Mental messages that a person voluntarily generates are simply inner speech, that is, verbal thinking. Most of our conscious thoughts are verbal. Although most people can think in non-verbal formats, such as visual imagery, verbal thinking dominates people’s conscious mental processing.
When someone reports hearing a message “in their mind,” usually they don’t mean that they have had a hallucination. A hallucination is a sensory experience in the absence of an external stimulus to cause the sensory input. Often, hallucinations are auditory, but hallucinations can also be experienced in the visual or other sense modalities. Auditory hallucinations are perceived as having the same qualities of sounds generated by external stimuli, and the person is often convinced of the objective reality of the experience.
Hearing a voice as if someone has spoken, without an external stimulus, is considered an auditory verbal hallucination. Hearing voices has commonly been thought of as a sign of mental illness, especially of a serious disorder such as schizophrenia. In fact, it has been estimated that hallucinations are one symptom experienced by approximately 75% of people diagnosed with schizophrenia, 20% to 50% of people with bipolar disorder, 40% in posttraumatic stress disorder, and 10% in major depression with psychotic features. Auditory hallucinations can be generated also by conditions other than mental illness, such as temporal lobe seizures, dementia, and infections of the brain.
Research supports the view that hearing hallucinatory voices is not by itself an indicator of mental illness. Estimates of the percentage of people in the general population without a known psychiatric illness who report auditory hallucinations vary widely. One review of seventeen surveys from nine countries found prevalence estimates as low as fewer than 1% to as high as 84%. Estimates of college students who have reported hearing hallucinatory voices have ranged from 13% to 71%. The wide range of estimates can be attributed in part to differences in definitions, survey instructions, and other methodological variations. Taking into consideration such methodological differences, some researchers estimate the prevalence of hearing voices in the general population to be between 5% and 28%, with 75% of people who report hearing voices to be psychologically healthy. Research suggests also that the prevalence of auditory verbal hallucinations varies by gender, age and culture.
Does it matter what the hallucinatory voices say or who the speaker seems to be? Studies with non-clinical populations have suggested that people are especially likely to hear hallucinatory voices during times of loss or bereavement. In one study, 30% reported hearing the voice of their deceased loved one within the first month of their death, and 6% still heard them a year later. In another study, 13% of persons heard the voice of their deceased spouse, including some who had been widowed up to 40 years prior to being interviewed.
Popular culture has long been fascinated with verbal hallucinations that contain religious content or are perceived as the voice of a religious figure, such as God. Biographers have reported that some saints began or transformed their religious work after hearing a directive from God. St. Francis of Assisi heard the voice of Christ saying: “Repair my house, which is falling into ruin.” Mother Teresa devoted her life to caring for those in need in Calcutta after she said she heard Christ directing her to. Such noteworthy examples of sacrifice and good works are in sharp contrast to the common stereotype of hearing supernatural commands as a sign of mental illness. The media highlights extreme and horrific cases that fuel the negative perception of supernatural experiences. Andrea Yates drowned all of her five children, maintaining that Satan told her to kill them. A psychiatric nurse testified that he observed Yates staring at her prison cell wall and talking to someone who wasn’t there the day after she had drowned them. There are few empirical studies that distinguish between religious and non-religious themes and voice identities in verbal hallucinations experienced by those suffering a mental disorder. The research estimates of spiritual themes in verbal hallucinations in patients range from 12% to 26%, with substantial differences across cultures. Whereas one study in South Africa reported that 51.8% of verbal hallucinations were attributed to God, another study in Pakistan found that only 6% reported hearing voices they identified as God.
Researchers have begun to explore the mechanisms that underlie the phenomenon of hearing voices in healthy individuals versus people challenged with a disorder. One main feature that distinguishes the inner speech of normal thinking from the voice-hearing phenomenon seems to be the content of the message. Unlike inner speech, messages conveyed in hallucinatory voices are not recognized by the individual as characteristic of their own thinking. In people with psychotic disorders, the content of hallucinatory messages is often derogatory, involving accusations, commands, or abuse. The difference between such negative messaging and their own thought patterns might be one reason they believe the voices are generated by external agents, including ghosts or religious entities such as God or demons. The emotional appraisal of the voice might well trigger emotional responses, such as heightened anxiety, that can make further hallucinatory instances more likely. By contrast, healthy people usually report that the content of the voices is either quite mundane (e.g., hearing their name) or positive (giving comfort or encouragement). Healthy individuals rarely report that the voices cause them distress or dysfunction in their daily life. There are, in other words, significant differences in hearing voices experienced by people with a psychiatric disorder and those without.
In the absence of other indicators, hearing voices might well be more common among healthy people than previously assumed. Differences in prevalence over the lifespan, between men and women, and across cultures remind us that a phenomenon associated with the disorder can also occur as the result of normal processes within the incredible complexity of the human mind. When someone says God has spoken to them, we might consider the long history of eminent thinkers who pondered the meaning of such experiences. At the beginning of the twentieth century, William James, who established the first experimental psychology laboratory in America at Harvard, proposed: “That vast literature of proofs of God’s existence drawn from the order of nature, which a century ago seemed so overwhelmingly convincing, today does little more than gather dust in libraries, for the simple reason that our generation has ceased to believe in the kind of God it argued for.” Unable to determine the existence or non-existence of God scientifically, James studied the psychological impacts of reported mystical encounters with the divine. His observations over a century ago parallel our contemporary research findings of positive effects of a variety of religious experiences. Confronting the impossibility of verifying the divine, James concluded that God is real in the reality of the impacts on those open to the possibility. Considering whether or not to choose such openness, James decided that it is more beneficial to act as if there is a transcendent that gives an ultimate meaning to life.
References
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Cook, C. (2015). Religious psychopathology: The prevalence of religious content of delusions and hallucinations in mental disorder. International Journal of Social Psychiatry, 61, 404-425.
De Leede-Smith, S., & Barkus, E. (2013). A comprehensive review of auditory verbal hallucinations: Lifetime prevalence, correlates and mechanisms in healthy and clinical individuals. Frontiers in Human Neuroscience, 7, 1-25.
James, W. (1991). The varieties of religious experience. New York, NY: Triumph Books. (Original work published 1902)
Kråkvik, B., Larøi, F., Kalhovde, A. M., Hugdahl, K., Kompus, K., Salvesen, Ø Stiles, T., C., & Vedul-Kjelsås, E. (2015). Prevalence of auditory verbal hallucinations in a general population: A group comparison study. Scandinavian Journal of Psychology, 56, 508-515.
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Waters, F., Blom, J. D., Jardri, R., Hugdahl, K., & Sommer, I. E. C. (2018). Auditory hallucinations, not necessarily a hallmark of psychotic disorder. Psychological Medicine, 48, 529-536.