Hearing Voices and Dissociation

“Once you hear the voices, you realize they’ve always been there. It’s just a matter of being tuned to them.”
(Mark Vonnegut, The Eden Express, 1975)

Abstract

While auditory hallucinations are considered a core psychotic symptom, central to the diagnosis of schizophrenia, it has long been recognized that persons who are not psychotic may also hear voices. There is an entrenched clinical belief that distinctions can be made between these groups, typically on the basis of the perceived location or the ‘third-person’ perspective of the voices. While it is generally believed that such characteristics of voices have significant clinical implications, and are important in the differential diagnosis between dissociative and psychotic disorders, there is no research evidence in support of this. Voices heard by persons diagnosed schizophrenic appear to be indistinguishable, on the basis of their experienced characteristics, from voices heard by persons with dissociative disorders or with no mental disorder at all. On this and other bases outlined below, we argue that hearing voices should be considered a dissociative experience, which under some conditions may have pathological consequences. In other words, we believe that, while voices may occur in the context of a psychotic disorder, they should not be considered a psychotic symptom.

Mark Vonnegut’s simple insight, expressed in his compelling autobiographical account of becoming psychotic in America in the 1960s, supports the position put forth in this paper, namely, that hearing voices should be considered a dissociative experience and not a psychotic symptom. This position is opposed to that of most clinicians and researchers, who believe that auditory hallucinations [1] (AH) are best considered a psychotic symptom, or that some AH should be considered psychotic and others dissociative. Nonetheless, our position is supported by both clinical and research evidence, including the evidence that many persons who hear voices do not show any (other) symptom of a mental disorder, and that no experienced characteristic of voices adequately distinguishes between those persons and others who are designated mentally ill. Accordingly, we propose that AH should, under no circumstances, be considered a psychotic symptom, despite the fact that they sometimes occur in the context of a psychotic disorder.

Throughout recorded history, AH have been understood in a number of ways. At various times, and under various circumstances, voices have been viewed as religious or spiritual phenomena (voices of gods, demons, angels), supernatural or psychic experiences (indicative of ghosts or telepathy), psychological experiences (post-traumatic, dissociative, psychotic), or entirely normal (voice of conscience, one’s own thoughts, creative inspiration, grief experiences, hypnopompic and hypnagogic experiences). Over the past 150 years, considerable effort has been expended in attempting to distinguish between these allegedly different forms of hallucinations, particularly along the lines of determining which voices merit the attention of physicians or mental health professionals and which do not.

Typically, these attempts have been mounted around certain perceived characteristics of auditory hallucinations, most commonly whether the voices appear to be emanating from outside the voice hearer or from inside their head (or some other part of their body). Classically, the latter, particularly when combined with ‘intact’ insight, have been referred to as ‘pseudo-hallucinations’, while only the former, i.e., ‘external’ hallucinations, have been accorded the label ‘proper hallucinations’ or ‘true hallucinations’ and considered a psychotic symptom (Jaspers, 1963/1913). However, insight is technically not an experienced aspect of the hallucination but a subsequent evaluation by the voice hearer (essentially equivalent to a secondary delusion). While it appears likely that there are some – as yet unidentified – personality or psychological factors which determine whether voices are heard internally or externally (and help to explain why one person can hear both internal and external voices and why some voices’ perceived source of location may change), there is no evidence that perceived location (or any other experienced characteristic of AH) map onto diagnostic categories or relevant clinical variables (such as treatment response).

Indeed, a recent study pointedly titled ‘On the non-significance of internal versus external auditory hallucinations’ examined this issue in a large cohort and concluded, “(T)he clinical relevance of location is not confirmed, and the conceptual clarity and clinical utility of the pseudohallucination is undermined” (Copolov, Trauer & Mackinnon, 2004, p. 5). Berrios and Dening (1996), in an exhaustive historical review, likened the concept of ‘pseudohallucinations’ to a “‘joker’ in the diagnostic game” whose fluidity allowed clinicians to “call into question the genuineness of some true hallucinatory experiences that do not fit into a pre-conceived psychiatric diagnosis” (p. 761).

Historical overview

Why some people do and others do not hear voices, and how to understand those voices, has been the subject of debate throughout the centuries. The two questions are closely related, as assumptions about voices have usually (but not always) been made by persons who do not hear voices, and their judgments have often been strongly colored by class, gender, and race beliefs. But was there a time when hearing voices was considered entirely normal? While the research data reviewed below suggests, currently, as many as 8-10% of the general population hear voices at some point in their life, one theorist believes that, millennia ago, all people heard voices. Julian Jaynes (1976), in a popular and controversial book, has argued that, until a few thousand years ago, humans did not possess self-reflective consciousness, and heard voices they attributed to gods, which guided their decision-making in small and large matters. He called this ancient mental structure the ‘bicameral’ mind, and argued that people who hear voices in modern times experience a relapse to this form of mind, primarily under the influence of extreme stress. Jaynes also predicted that hearing voices would be associated with activity in the right temporal lobe, analogous to the left hemisphere speech recognition/understanding center known as Wernicke’s area. While Jayne’s highly speculative theory has received little attention in psychiatric circles, there is now some evidence, reviewed below, in support of his contentions.

For much of recorded human history, hearing voices was associated with divine inspiration, or Satanic possession; as such, those who decided the source of others’ voices (often on nebulous criteria) were typically associated with the Christian Church or other religions (Sarbin & Juhasz, 1967). Then, in the mid 16th century, Teresa of Avila, fearful that her nuns would be persecuted by the Inquisition for the voices they heard, argued that some voices should not be seen as divine or devilish, but as the result of more mundane physical problems. She wrote that some voices were due to melancholy, a ‘weak’ imagination, or drowsiness, sleep or sleep-like states (Sarbin & Juhasz, 1967). Importantly, Teresa wrote that such individuals should be treated ‘as if’ they were sick, but Sarbin and Juhasz note that the ‘as if’ was quickly dropped as the phenomenon of hearing voices became medicalized.

The medical perspective became the dominant mode of understanding hallucinations (in all sensory modalities) in the 19th century, a term given its modern definition by Esquirol in 1832. Esquirol distinguished hallucinations from illusions on the basis that the latter involved genuine sensory perceptions (plus distortions); he stated that a person hallucinating “ascribes a body and an actuality to images that the memory recalls without intervention of the senses” (Esquirol, 1832, cited in Bentall, 1990, p. 82). While Esquirol believed that hallucinations were invariably pathological, a dispute developed in subsequent decades as to whether this was so.

This question culminated in a series of debates at the Société Médico-Psychologique in Paris, foreshadowing many of the debates still held today. As summarized by Berrios & Dening (1996), these discussions considered “whether all hallucinations were abnormal; and whether location (internal versus external) and insight (present versus absent) were relevant factors to the definition of pathological hallucinations” (p. 756). Berrios & Dening (1996) note that these important debates were overlooked by Karl Jaspers, in his highly influential General Psychopathology (1963/1913), who attributed the distinctions to an important figure from the 1880s, Victor Kandinsky.

Kandinsky was important not only because, unlike the French theorists, he himself experienced hallucinations, but also because he claimed to experience both ‘true’ (TH) and ‘pseudo’ (PH) hallucinations, and endeavored to distinguish between the two[3]. Kandinsky argued that only TH involved the activity of a subcortical perception center (just like genuine perceptions), while PH involved only the activity of a center for apperception (a term rarely used now, which means the state of being conscious of perceiving) along with a ‘center for abstract, unconscious images’ (Berrios & Dening, 1996). Thus, Kandinsky decided that PH were as sensorially vivid as TH, but lacked the ‘external objectivity’ of TH because in only the latter was the subcortical perception center activated. He also believed

that PH were internally localized.

Auditory hallucinations and differential diagnosis

Auditory hallucinations were not central features of either Kraepelin’s Dementia Praecox or Bleuler’s Schizophrenia. For Bleuler, AH, while occurring frequently in schizophrenia, were derivative of the central disturbance of loosening of associations, and were also common in other disorders. A much closer link between AH and schizophrenia, however, was forged by Kurt Schneider (1959), whose position underpins the diagnosis of schizophrenia in the DSM-IV (American Psychiatric Association, 1994) and ICD-10 (WHO, 1993). Schneider felt that certain AH, particularly those commenting on an individual’s thoughts or behaviors or two or more voices conversing with each other, were pathognomic (only one symptom required for a diagnosis) for schizophrenia; he also thought that hearing one’s thoughts aloud was characteristic of the disorder. The first two symptoms were adopted by the American Psychiatric Association for the diagnosis of schizophrenia, and now form two of the three pathognomic symptoms (the third, also problematic, is ‘bizarre’ delusions[4]). Interestingly, while the APA had specifically linked external AH to schizophrenia in early DSMs, this link was eliminated (presumably for lack of empirical evidence) in the DSM-IV (APA, 1994).

There is, however, considerable evidence that AH, particularly those considered pathognomic for schizophrenia, are not only not unique to that disorder but occur more frequently in dissociative identity disorder (Honig et al, 1998; Kluft, 1987; Ross et al, 1989; Ross et al, 1990). In light of this observation, several authors have argued for new dissociative diagnostic categories (‘Dissociative hallucinosis,’ Nurcombe et al, 1996; ‘Dissociative subtype of schizophrenia,’ Ross, 2004) in which AH are featured prominently.

Other authors have taken a different tack, addressing AH directly by proposing new classificatory systems. Thus, Van der Zwaard & Polak (2001), after reviewing the concept of pseudohallucinations, argue that PH should be broken up into several categories, namely:

• nonpsychotic hallucinations (e.g., ‘isolated’ nonpsychotic hallucinations, such as occur in grief reactions, AH arising from sensory deprivation, and ‘vivid internal imagery’, typical in dissociative disorders),
• partial hallucinations, such as ‘fading hallucinations with increasing insight’
• transient hallucinations (such as ‘short lapses’ in reality testing in persons diagnosed with borderline personality disorder).

This classification appears to offer little improvement over the simple PH/TH dichotomy; it seems difficult to justify calling AH in dissociative disorders ‘imagery’ and ‘partial hallucinations’ appears to be a nonsensical concept. Further, there is evidence that AH in borderline personality disorder are not transient, as has been generally believed, but in fact are ‘ongoing and pervasive’ (Yee et al, 2005). In light of this, Yee et al (2005) has offered an alternative classification, namely that AH be split up into:

• normative,
• traumatic-intrusive,
• psychotic,
• organic hallucinations.

But is there any evidence that AH can be successfully carved up in this (or any other) manner?

Research evidence

A number of relevant research studies have now been conducted, examining the prevalence of hallucinations in the general population, contrasting voices heard by patients with non-patients or, within clinical populations, assessing whether certain characteristics of voices predict clinical or outcome variables. Some studies have also demonstrated clear links between AH and dissociative experiences.

AH in non-psychiatric patients

The studies assessing the prevalence and nature of auditory hallucinations in non-psychiatric populations are illustrated in Table 2.

Six large-scale studies, based primarily in the UK, the Netherlands, and the U.S., have found rates of between 0.6% to 8.2% annual or lifetime prevalence of hallucinations in the general population (excluding, to a greater or lesser degree, identified psychiatric patients)[5]. Three studies of selected non-psychiatric samples, primarily university students or medical patients, have reported slightly higher rates, ranging from 2%-13%.

The first large-scale study to assess hallucinations in the general population was carried out primarily in England between 1889 and 1892, and involved interviews with 17,000 adults (Sidgewick, Johnson, Myers, et al., 1894). This study, known as the Sidgewick study after the first author, was conducted by the Society for Psychical Research (SPR), an organization dedicated to researching psychic phenomena, such as telepathy. As such, a number of the interviewers may have been biased toward discovering hallucinations in non-psychiatric patients. However, the study has been described as well designed, and incorporated a number of relevant exclusion criteria (Tien, 1991). Sidgewick et al found approximately 10% of their participants to have experienced visual, auditory, or tactile hallucinations over their lifetime, just under 7% when corrected for sleep-related experiences. Most of those hallucinations were visual. Those experiencing auditory hallucinations decreased from 2% of those in their 20s, to just under 1% for those over 30. In addition, a gender bias was recorded, with women experiencing more hallucinations than men.

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Footnotes

• [1] Technically, the term auditory hallucinations refers to any sound heard in the absence of appropriate external stimuli, not only voices. For example, during post-traumatic flashbacks, a wide range of sounds related to a trauma, such as police sirens, gunshots, etc., may be heard. However, for the purposes of this article, auditory hallucinations will be used exclusively to refer to the hearing of voices. While voices are sometimes referred to as ‘verbal’ hallucinations, the term auditory hallucinations is more familiar and as such is preferred here.
• [2] We do not take a position in this paper as to whether AH may, under some circumstances, represent a ‘genuine’ spiritual experience. Even if that is allowed, however, adequate means to distinguish such experiences from AH better explained by psychological (dissociative) mechanisms remains to be established. In other words, at least some AH interpreted by the voice hearer as spiritual may actually derive from a disowned aspect of themselves. At this point, we cannot adequately distinguish between the two on the basis of reported experience.
• [3] The term ‘pseudo-hallucination’ was coined in 1868 by Hagen to refer to hallucinations with less sensory ‘fullness’ than perceptions (or ‘true’ hallucinations), which derived from an ‘organ of apperception’, and which were due to the spontaneous activity of memory (Berrios & Denning, 1996). Almost all theorists have considered ‘pseudo-hallucinations’ to be essentially normal phenomena.
• [4] Examples given of bizarre delusions are beliefs of loss of control of mind or body, and include delusions of control, and delusions of thought insertion and thought withdrawal (APA, 1994). Both of these sets of delusions, along with voices commenting and conversing, also delimit three of the four pathognomic symptoms of ICD-10 Schizophrenia (WHO, 1993). Some question whether these should be called delusions at all, as opposed to adequate descriptions of unusual/anomalous experiences (Spitzer, 1990). All are common in DID, where they are typically understood as deriving from the influence of one part of the personality on another (Kluft, 1987; Ross et al., 1989; Ross et al., 1990).
• [5] A seventh, Wiles et al (2006), is not reported here because incidence and not prevalence data were used. Of interest, however, is that just over 5% of almost 2000 persons, without a psychiatric history and not meeting criteria for a psychotic disorder, reported at least one of four narrowly defined psychotic symptoms (thought insertion, paranoia, ‘strange experiences’ and hallucinations; Wiles et al, 2006).
• [6] Oulis et al (1995) reported that patients had little difficulty in identifying the location from which their voice(s) appeared to emanate, a finding confirmed by most other researchers.
• [7] As Karen also heard two or more voices conversing with each other, her voices fulfilled both of the pathognomic AH criteria for DSM-IV schizophrenia (i.e., voices commenting and voices conversing).
• [8] Indeed, Morrison’s (1998) model of how ‘normal’ AH lead to psychopathology, in which he argues that AH may be ‘misinterpreted’ as “threatening the physical or psychological integrity of the individual,” leading to decreased mood, hyperarousal and hypervigilance, along with avoidance behaviors (p. 296), almost exactly mirrors current conceptions of PTSD.