A comprehensive review of auditory verbal hallucinations: lifetime prevalence, correlates and mechanisms in healthy and clinical individuals

Abstract

Over the years, the prevalence of auditory verbal hallucinations (AVHs) have been documented across the lifespan in varied contexts, and with a range of potential long-term outcomes. Initially the emphasis focused on whether AVHs conferred risk for psychosis. However, recent research has identified significant differences in the presentation and outcomes of AVH in patients compared to those in non-clinical populations. For this reason, it has been suggested that auditory hallucinations are an entity by themselves and not necessarily indicative of transition along the psychosis continuum. This review will examine the presentation of auditory hallucinations across the life span, as well as in various clinical groups. The stages described include childhood, adolescence, adult non-clinical populations, hypnagogic/hypnopompic experiences, high schizotypal traits, schizophrenia, substance induced AVH, AVH in epilepsy, and AVH in the elderly. In children, need for care depends upon whether the child associates the voice with negative beliefs, appraisals and other symptoms of psychosis. This theme appears to carry right through to healthy voice hearers in adulthood, in which a negative impact of the voice usually only exists if the individual has negative experiences as a result of their voice(s). This includes features of the voices such as the negative content, frequency, and emotional valence as well as anxiety and depression, independently or caused by voices presence. It seems possible that the mechanisms which maintain AVH in non-clinical populations are different from those which are behind AVH presentations in psychotic illness. For example, the existence of maladaptive coping strategies in patient populations is one significant difference between clinical and non-clinical groups which is associated with a need for care. Whether or not these mechanisms start out the same and have differential trajectories is not yet evidenced. Future research needs to focus on the comparison of underlying factors and mechanisms that lead to the onset of AVH in both patient and non-clinical populations.

An Anxious 17-Year-Old Girl Who Hears Voices Only at Sleep Onset

“…4 AVH in children are usually transitory, resolving with time, unless they are associated with a severe underlying psychiatric illness. 5 AVH have also been reported in anxiety and posttraumatic experiences. 6 Depending on the traumatic experience, auditory hallucinations can change in character and quality.…”

“…Other conditions that can present with predominantly visual hallucinations but can also include auditory hallucinations are migraines, dementia, narcolepsy, REM behavior disorder, and occipital seizures. 5 Treatment options for exclusively hypnagogic AVH are aimed at the underlying condition. Sleep extension is commonly recommended when sleep insufficiency is suspected.…”

What Do We Know About the Correlates and Underlying Causes of Auditory Hallucinations in Nonpsychotic Children and Adolescents, and What Are the Implications for Diagnosis and Treatment?

“…While cognitive models suggest that auditory hallucinations arise from the misattribution of inner speech to an external source, Allen et al, (2005) found that it was the influence of high levels of emotion, particularly anxiety, on cognitive functioning that was implicated in triggering hallucinations. Some support for this position was offered by de Leede-Smith and Barkus (2013) who, observing the close association between auditory hallucinations and PTSD, suggested that trauma acting on the individual via intrusive thoughts and memories may result in hallucinations. More specifically, Hugdahl (2009) proposed that hallucinations represented bottom-up perceptual misrepresentations due to a failure of top-down (cortical/pre-frontal) inhibition as a consequence of high levels of emotional stress.…”

“…de Leede-Smith and Barkus (2013) were clear in their view that auditory hallucinations should no longer be recognized as a diagnostic indicator as the presence of such hallucinations is not intrinsically related to the outcome of the individual. Schreier (1998) considered that prognosis was likely to be more related to aspects of the child's condition rather than to the fact that they heard voices and, in a later paper (Schreier, 1999), advised that hallucinations seen in children needed to be regarded in the context of the rest of the clinical picture.…”

“…One of the best researched triggers implicated in the generation of auditory hallucinations (in the absence of other factors such as brain injury or drug use) is that of traumatic life experiences (de Leede-Smith & Barkus, 2013). With specific reference to clinical populations of nonpsychotic children, the presence of auditory hallucinations has typically been associated with a range of life stresses and adversities resulting in significant levels of emotional distress.…”