Auditory hallucinations commonly referred to as “voices” has been a feature of many psychiatric illnesses. Auditory hallucinations involve perceiving sound without an auditory stimulus. It is presumed to be pathology or a symptom that reflects ‘psychosis’ (a break from reality) caused by substance abuse or other medical/psychiatric illnesses that needs to be treated. Other research has shown auditory hallucinations are correlated with an increase in activity of the thalamic and strietal subcortical nuclei, hypothalamus and paralimbic regions in the brain. Dopamine neurotransmitters and metabolism are what is currently implicated and treated by a variety of antipsychotic medications. The treatment and resolution of this symptom has been the way medicine and psychiatry traditionally tracks improvement in patients.
There is on-going research that supports the prevalence of auditory hallucinations with a lack of other conventional psychotic symptoms (such as delusions or paranoia). Differentiating actual auditory hallucinations from “sounds” or a normal internal dialogue is important since the latter phenomena is not indicative of mental illness.
This phenomenonological survey by Angela Woods et al that was done on 153 subjects is novel in that it surveys a broad range of people with many different diagnoses. However, it is important to note that the survey was placed on-line and advertised for people who ‘heard voices’. Hence, the results do not reflect the incidence of auditory hallucinations in the general or illness-specific populations. The study had other limitations 2.5 times as many women as men completed the survey, it was only offered in English, there was no verification of self-reports and the ‘coding’ of characteristics was done by the researchers but not independently volunteered. Acutely ill people were “certainly” (by researchers’s admission) underrepresented in this survey. The authors in their own self-assessment note: “Although people from black and minority ethnic origins are up to nine times more likely than people from other ethnic origins to present with symptoms of psychosis, ‘they are underrepresented in this study’.”
This study is interesting in that it raises questions of what “imagined sound” is: passive or uncontrolled imagined perceptions vs. perceptual hallucinations The results show that 81% heard multiple voices with different “character “ qualities (that means they were of specific age, gender and had distinct identities) that were expressed internally within the head (as opposed to external as if the voices heard ‘were in the room’) and were ‘conversational’ (that is the voices or thoughts talk with the individual or with each other). Slightly less than half of the surveyed group heard it as “voices” while the others “heard” it as thoughts or mixed thoughts and voices. Two-thirds (66%) reported bodily sensations (referred to as tactile hallucinations in general psychiatry) and these sensations were associated with abusive and/or violent voices. Of note, is that one-third reported positive emotions, one-third neutral emotions and the rest emotions of anxiety, depression, fear and stress. Additionally, the survey reported that ‘command hallucinations’ (which have been assumed in general practice to be indicative of high risk of harm to self and others) was only prevalent in 5% of those participating.
*This study has no current useful clinical application for people currently suffering from hallucinations (auditory or tactile). Readers who are currently suffering or have family members suffering from internal voices or thoughts should see their doctor for guidance.
Although this survey was biased (in terms of those who responded) and unverified (as are any anonymous internet surveys), it has two important strengths. First, it shows the potential for gathering large amounts of data very quickly via mass-distributed questionnaires [if we can only solve the verification problem, the possibilities are quite substantial]. Second, it highlights the approach to understanding symptoms independent of specific diagnoses (the current Research Domain Criteria approach of NIMH, which suggests that we will better understand the underlying neurobiology of behavior when we focus on more molecular symptoms rather than on loosely defined syndromes). In other words, we have a better chance of understanding the underlying neurobiology, neurocircuitry, and genetics of a specific symptoms like auditory hallucinations – regardless of what the supposed “illness” is – than we do of understanding the neurobiology of an entire syndrome like schizophrenia (because so many attempts to do that have failed).