Shame and HV in a non-clinical population
The experience of hearing voices can be correlated with shameful experiences in several ways. Like other emotions such as sadness, shame could shape the content and triggering the onset of voices (40). Firstly, HV can represent a source of significant distress in terms of content, meaning ascribed, and the relationship between the voice and the hearer. Shame was found to be related to the negative content, qualities of the heard voices and the subjective ratings of deprivation (49). This finding supports the idea of mirroring between voice hearers’ experience and the quality of voice-hearer relationship: for instance, in case of feelings of inferiority and defectiveness concerning the self, this is mirrored in the voice being experienced as powerful, dominant, harming, and intrusive (56). Given that induction of shame led to increased levels of intrusive thoughts and working memory impairments (38), there are reasons to expect that shame in response to a stressful event can be involved in the elicitation of HV (57). Therefore, shame can be not only simply correlated with this phenomenon, but it may be a causal factor in the onset of HV (40). One possible function of this process is proposed by McCarthy-Jones that evidenced that shame could elicit HV to encourages submissive and self-protective behaviours avoiding situations that can be potentially threatening for one’s identity. For example, this can be true in people who lived negative past experiences of stigmatization, bullying or neglect. Within this perspective, shame can be related to HV playing an adaptive function that aids survival protecting people from further unpleasant experiences (40).
Finally, shame can emerge because of HV. The experience of HV per se can constitute a significant source of stress for cultural reasons (58, 59). Even when HV is appraised by their hearing voice’s experience as benign, positive, and controllable, this phenomenon is considered a social taboo, as it is difficult to talk about voices “without being looked at in a strange way”(30, 60, 61). People who hear voices reported a lack of understanding by friends, families and even professionals and, as a result, many people hide these experiences, because of the fear of social judgment and stigma (61, 62). People who experience hearing voices may feel themselves negatively judged by others and they can experience shame perceiving themselves as defective or inadequate (32).
Guilt and HV in a non-clinical population
As with shame, guilt may influence people’s HV. This can be common in people who experienced stressful life events that are linked with repentance or regret (40). HV with guilty content can be shown not only by veterans or people who experienced war or conflicts but also by people who experienced emotionally overwhelming events related to mistakes or bad actions. This voice represents the introjected negative thoughts and it ranges from unconscious or subliminal to fully conscious (63). Guilty voices can be associated with emotional parts associated with self-criticizing narratives that can range from a benign advisor to a maladaptive judge (64). In their worst expression, feelings of guilt can be a key driver to HV related to past traumatic events (e.g. abuse, experiences of war or bullying) or be the content of intrusive and very disruptive HV in schizophrenia (40).
Although their relationship with pathological disorders, guilty HV can also have the role of establishing a precise responsibility related to personal negative experiences. Therefore, HV that show guilty contents may also give a perception of order towards stressful events that otherwise would seem even more frightening and chaotic. This can give the transgressor a sense of control over negative events and help avoid similar mistakes in the future. HV of guilt can be seen as an internal reminder of past mistakes that can be viewed as the source of helpful albeit challenging messages. Within this perspective, HV of guilt can be related to an internalized voice of moral authority that can guide interpersonal behaviour enhancing social relationships and restoring equities (16).
Shame and guilt HV neuropsychological aspects
Cognitive functions and inhibitory functions, context binding, reality monitoring and metacognition play a relevant role in the development of AVHs. Their dysfunction may lead to the emergence of redundant and/or irrelevant or distractive information from the long-term memory to awareness, resulting in AVHs. The negative emotional valence of AVH could be related to the activation of the right Broca’s area (50, 65). In particular, AVHs were found to be similar to the automatic speech utterances that are generally generated by the right hemisphere of patients with aphasia. Due to the role of Broca’s area in the inhibitory process, its relationship with the repetitive simple is considered plausible (66). Other studies noted a consistent activation of both amygdala and parahippocampal gyrus during processing the negative content of the heard voices (67). These data are particularly consistent with other studies that found specific activations in the anterior cingulate cortex, parahippocampal gyrus related to shame and in the amygdala and insula for guilt(35).
Moreover, Van Lutterveld and colleagues found that, in resting-state networks, the role of the amygdala tends to decrease, and Vercammen found its reduced connectivity with the left temporoparietal region, which is recognised to be generally overactive during AVHs (68, 69).
De Boer and colleagues noted that individuals with AHVs tend to be less sensitive than the others in the auditory verbal recognition and they show a higher false alarm rate if compared with people without AVHs. This may be related to an overload of the working memory that can be found within guilt and shame activations(38).
Shame, guilt and HV in psychotherapy
Even if the notion of hearing voices is not necessarily a pathological phenomenon, psychotherapy literature from very different orientations explored the multi-voiced nature of the self (70, 71). Working on the inner voice of guilt and shame can be a very enriching experience within the therapy session, even when HV don’t cause a pathological impairment. Different voices can be related to a different part of the self, some of which are more dominant than others, that may have different roles and relationships with each other’s (72). HV with guilty or shameful content can be related to a self-criticizing part of the self that even in a non-clinical population, when is not properly accepted, can be extremely stressful. Within this context, psychotherapy can be the safe space where the therapist encourages clients to listen to their self-criticizing part and try to understand the reason for their shameful and guilty messages. This can start a new constructive dialogue between self-criticizing parts and other parts more related to compassionate and non-judgment (73). Clients can be encouraged to explore the content of that voices that are often tied to previous negative experiences that they can learn to manage and resolve (74). Within this perspective, the therapist and the client start to give equal space to all the parts of the self-fostering the development of a richer and more integrated constellation of voices that express different parts of the client's identity (75).
Limitations and strengths
The strength of this systematic review is a focus on guilt and shame as related to auditory hallucinations in non-clinically impaired people. Nevertheless, the consistency of the results obtained, considering the variety of the type of articles included, the research design, the instruments adopted, and the statistical analyses carried out, prevents generalizability. Moreover, the sample size of these studies is small and often includes great heterogeneity in terms of age and gender, as well as no follow-up.
Other limitations of this review concern the search strategy. Although our literature search was conducted in eight databases and several search terms were applied, the search may not be exhaustive. Eligible studies are only from 7 countries and most of them were carried out in the USA.
Implications for practice and research
Most studies included in our review focused on shame or on guilt and not on both, and this makes it complex to examine whether they do not also influence the occurrence of HVs together or arise together. Psychological interventions are suggested to target maladaptive appraisals and allow the construction of affect regulation strategies, including shame and guilt, which may play an important role in increasing the distress associated with AVHs, in those who are not clinically impaired. In addition, longitudinal studies with long follow-ups would be essential to highlight the direction of the relationship between AVHs, shame and guilt. Thus, there is a need to establish the longer-term association of shame, guilt and hearing voices. As well their effects on longer term mental health outcomes and hearing voices themselves, shame and guilt may contribute to adverse consequences such as isolation or increasing rates of depression, anxiety, or other mental disorders. Indeed, more systematic exploration is needed about how shame and guilt affect hearing voices in non-clinical people and viceversa.
This systematic review also can contribute to stress the relevance of understanding, targeting of specific psychological therapies, and informing of social policy (around the importance of an equal society) for those who hear voices.