A final common pathway to hearing voices: examining differences and similarities in clinical and non-clinical individuals

Voice phenomenology as a mirror of the past

BACKGROUND

Post-traumatic mechanisms are theorised to contribute to voice-hearing in people with psychosis and a history of trauma. Phenomenological links between trauma and voices support this hypothesis, as they suggest post-traumatic processes contribute to the content of, and relationships with, voices. However, research has included small samples and lacked theory-based comprehensive assessments.

METHOD

In people with distressing voices (n = 73) who experienced trauma prior to voice-hearing, trauma-voice links were assessed both independently and dependently (descriptions were presented and rated separately and together, respectively) by both participants and researchers. A structured coding frame assessed four types of independent links (i.e. victimisation type, physiological-behavioural, emotional, and cognitive response themes including negative self-beliefs) and three types of dependent links: relational (similar interaction with/response to, voice and trauma); content (voice and trauma content are exactly the same); and identity (voice identity is the same as perpetrator).

RESULTS

Independent links were prevalent in participants (51-58%) and low to moderately present in researcher ratings (8-41%) for significant themes. Identification of negative self-beliefs in trauma was associated with a significantly higher likelihood of negative self-beliefs in voices [participants odds ratio (OR) 9.8; researchers OR 4.9]. Participants and researchers also reported many dependent links (80%, 66%, respectively), most frequently relational links (75%, 64%), followed by content (60%, 25%) and identity links (51%, 22%).

CONCLUSION

Trauma appears to be a strong shaping force for voice content and its psychological impact. The most common trauma-voice links involved the experience of cognitive-affective psychological threat, embodied in relational experiences. Trauma-induced mechanisms may be important intervention targets.

Investigating predictors contributing to the expression of schizotypy during the COVID-19 pandemic

The coronavirus (COVID-19) pandemic has caused major disruptions to social and other forms of functioning, which may influence schizotypy expression. The current study aimed to explore possible distal and proximal predictors contributing to schizotypy in a sample of the Australian general population during the COVID-19 pandemic. The COvid-19 and you: mentaL heaLth in AusTralia now survEy (COLLATE) project is an online mental health study aimed at tracking key mental health indicators over the progression of the pandemic. Adults residing in Australia were invited to take part using non-discriminative snowball sampling. Demographic-clinical information was collected for 850 participants in either October 2020 or January 2021. To assess schizotypy facets, the Launay-Slade Hallucinations Scale-Extended (LSHS-E) and Peters Delusions Inventory (PDI-21) were used to measure hallucination and delusion proneness respectively. Generalised linear models (with gamma and negative binomial distributions) were employed. Age, negative emotions and loneliness significantly contributed to both hallucination and delusion proneness; gender, education and religiosity also significantly contributed to delusion proneness, in the final regression models. Our study corroborated the specific contribution of loneliness, amongst other factors, in the prediction of schizotypy facets. Tackling loneliness represents a public health challenge that needs to be urgently addressed, especially in the face of the ongoing COVID-19 pandemic.

External speech processing and auditory verbal hallucinations: A systematic review of functional neuroimaging studies

It has been documented that individuals who hear auditory verbal hallucinations (AVH) exhibit diminished capabilities in processing external speech. While functional neuroimaging studies have attempted to characterise the cortical regions and networks facilitating these deficits in a bid to understand AVH, considerable methodological heterogeneity has prevented a consensus being reached. The current systematic review investigated the neurobiological underpinnings of external speech processing deficits in voice-hearers in 38 studies published between January 1990 to June 2020. AVH-specific deviations in the activity and lateralisation of the temporal auditory regions were apparent when processing speech sounds, words and sentences. During active or affective listening tasks, functional connectivity changes arose within the language, limbic and default mode networks. However, poor study quality and lack of replicable results plague the field. A detailed list of recommendations has been provided to improve the quality of future research on this topic.

Characteristics of non-clinical hallucinations: A mixed-methods analysis of auditory, visual, tactile and olfactory hallucinations in a primary voice-hearing cohort

Phenomenological studies involving hallucinations in non-clinical populations have been relatively neglected, especially within the non-auditory realm. Relevant knowledge would help further a more nuanced understanding of the psychosis continuum. Participants (N=33) were non-clinical voice-hearers, who have experienced auditory verbal hallucinations, but with no known mental health diagnosis and not taking any prescribed psychiatric medications. A comprehensive hallucinations phenomenology interview was conducted to assess physical, cognitive and emotional characteristics of hallucinatory experiences across sensory domains. Mixed methods analysis was employed. Characteristics of reported AVHs were mostly in agreement with existing knowledge, though some deviations did exist (e.g. controllability). In addition, 50%, 24% and 29% of our voice-hearing sample experienced hallucinations in the visual, tactile and olfactory domains at least once a week. In contrast, delusions and disordered thinking were rare. Qualitative thematic analysis yielded added phenomenological insights into contextual triggers as well as the content and perceived purpose(s) of multisensory hallucinations. Our findings highlight lesser-reported data that hallucinations in non-auditory domains are relatively frequent in non-clinical voice-hearers. However, other psychotic-like symptoms (i.e. delusions and thought disorder) seem less common. These insights should be considered in the context of the psychosis continuum argument.

Social interaction skills and depressive symptoms in people diagnosed with schizophrenia: The mediating role of auditory hallucinations

Past studies have presented evidence that depressive symptoms are affected in different ways by social interaction skills and auditory hallucinatory symptoms in people with schizophrenia. However, few studies have focused on examining the relationship among auditory hallucinatory severity, social interaction skills, and depressive symptoms. This study aimed to explore the mediating effect of auditory hallucinatory severity on social interaction skills and depressive symptoms in people with long-term schizophrenia. We propose that auditory hallucination severity functions as a mechanism through which impaired social interaction skills increase depressive symptoms. In this study, a convenience sample of 186 people with schizophrenia was obtained from hospital-based rehabilitation wards. Four instruments were used: A demographic data questionnaire, the Assessment of Communication and Interaction Skills-Chinese version, the Characteristics of Auditory Hallucinations Questionnaire, and the Beck Depression Inventory II. To investigate the mediating effect of auditory hallucinatory severity after controlling for six covariates, we tested an indirect effect in a simple mediation model using the SPSS macro PROCESS, which is a regression-based approach. The indirect effect and the results of Sobel's test were significant (Z = -2.824, P = 0.005), which confirms that auditory hallucination severity mediates social interaction skills and depressive symptoms. This finding suggests that psychiatric nurses must teach people with schizophrenia to use auditory hallucination management strategies to prevent them from becoming immersed in auditory hallucinations and reducing their social interaction with the real world, so that depressive symptoms can be improved.

What is distressing about auditory verbal hallucinations? The contribution of goal interference and goal facilitation

OBJECTIVES

Distressing and pleasant/positive voices (auditory verbal hallucinations) are common in both clinical and non-clinical voice-hearers. Identifying factors that contribute to emotional reactions to voices is essential for developing effective psychological interventions. Several theories propose that facilitation and interference with personal goals are important predictors of distress and well-being. This study examined whether voice-related distress is related to the degree to which voices interfere with personal goals, and whether pleasantness of voices is influenced by the extent to which they facilitate goals.

DESIGN

Cross-sectional with clinical and non-clinical voice-hearers.

METHOD

Twenty-two clinical and 18 non-clinical voice-hearers completed interviews and self-report measures assessing (1) personal goals, (2) content, characteristics, and affective reactions to voices, and (3) ratings of the extent to which voices facilitated and/or interfered with achievement of important personal goals.

RESULTS

Affective reactions were strongly correlated with measures of goal interference and goal facilitation. Regression analyses revealed that these associations remained significant when controlling for important covariates (e.g., participant grouping; content, frequency and duration of voices). Goal interference was specifically associated with distress, whereas goal facilitation specifically predicted perceived pleasantness of voices.

CONCLUSIONS

This study provides a novel perspective on the factors that might contribute to distress in people who hear voices. The findings suggest that perceived impact of voices on valued personal goals may be an important contributor of voice-related distress. We propose that clinical assessments, formulations, and interventions could benefit from the careful analysis of the perceived impact of voices on goals.

PRACTITIONER POINTS

These findings suggest that variability in voice-related distress is closely linked to the perceived impact of voices on personal goals. These strong effects observed highlight the importance of considering the role of personal goals in future research on the psychological mechanisms leading to distress associated with voice hearing. Psychological assessments may benefit from the careful exploration of the impact of voice hearing on valued goals, and interventions promoting control over personal goals may be explored as treatment options for clients with distressing voices.

Auditory verbal hallucinations: Social, but how?

Auditory verbal hallucinations (AVH) are experiences of hearing voices in the absence of an external speaker. Standard explanatory models propose that AVH arise from misattributed verbal cognitions (i.e. inner speech), but provide little account of how heard voices often have a distinct persona and agency. Here we review the argument that AVH have important social and agent-like properties and consider how different neurocognitive approaches to AVH can account for these elements, focusing on inner speech, memory, and predictive processing. We then evaluate the possible role of separate social-cognitive processes in the development of AVH, before outlining three ways in which speech and language processes already involve socially important information, such as cues to interact with others. We propose that when these are taken into account, the social characteristics of AVH can be explained without an appeal to separate social-cognitive systems.

Experiences of hearing voices: analysis of a novel phenomenological survey

BACKGROUND

Auditory hallucinations--or voices--are a common feature of many psychiatric disorders and are also experienced by individuals with no psychiatric history. Understanding of the variation in subjective experiences of hallucination is central to psychiatry, yet systematic empirical research on the phenomenology of auditory hallucinations remains scarce. We aimed to record a detailed and diverse collection of experiences, in the words of the people who hear voices themselves.

METHODS

We made a 13 item questionnaire available online for 3 months. To elicit phenomenologically rich data, we designed a combination of open-ended and closed-ended questions, which drew on service-user perspectives and approaches from phenomenological psychiatry, psychology, and medical humanities. We invited people aged 16-84 years with experience of voice-hearing to take part via an advertisement circulated through clinical networks, hearing voices groups, and other mental health forums. We combined qualitative and quantitative methods, and used inductive thematic analysis to code the data and χ(2) tests to test additional associations of selected codes.

FINDINGS

Between Sept 9 and Nov 29, 2013, 153 participants completed the study. Most participants described hearing multiple voices (124 [81%] of 153 individuals) with characterful qualities (106 [69%] individuals). Less than half of the participants reported hearing literally auditory voices--70 (46%) individuals reported either thought-like or mixed experiences. 101 (66%) participants reported bodily sensations while they heard voices, and these sensations were significantly associated with experiences of abusive or violent voices (p=0·024). Although fear, anxiety, depression, and stress were often associated with voices, 48 (31%) participants reported positive emotions and 49 (32%) reported neutral emotions. Our statistical analysis showed that mixed voices were more likely to have changed over time (p=0·030), be internally located (p=0·010), and be conversational in nature (p=0·010).

INTERPRETATION

This study is, to our knowledge, the largest mixed-methods investigation of auditory hallucination phenomenology so far. Our survey was completed by a diverse sample of people who hear voices with various diagnoses and clinical histories. Our findings both overlap with past large-sample investigations of auditory hallucination and suggest potentially important new findings about the association between acoustic perception and thought, somatic and multisensorial features of auditory hallucinations, and the link between auditory hallucinations and characterological entities.

FUNDING

Wellcome Trust.