Hallucinations in nonpsychotic disorders: toward a differential diagnosis of "hearing voices"

Effects of expectations and sensory unreliability on voice detection - A preregistered study

The phenomenon of "hearing voices" can be found not only in psychotic disorders, but also in the general population, with individuals across cultures reporting auditory perceptions of supernatural beings. In our preregistered study, we investigated a possible mechanism of such experiences, grounded in the predictive processing model of agency detection. We predicted that in a signal detection task, expecting less or more voices than actually present would drive the response bias toward a more conservative and liberal response strategy, respectively. Moreover, we hypothesized that including sensory noise would enhance these expectancy effects. In line with our predictions, the findings show that detection of voices relies on expectations and that this effect is especially pronounced in the case of unreliable sensory data. As such, the study contributes to our understanding of the predictive processes in hearing and the building blocks of voice hearing experiences.

Representation of Voice Hearing Groups by French Mental Health Professionals

Hearing voices groups (HVGs) are an alternative way of treating acoustic-verbal hallucinations. Although they have been developing in France for the last decade, they have lagged behind their international expansion. The representations that circulate about their functioning and their effects are likely to influence the referral to these groups by mental health professionals. We created and used a questionnaire to survey mental health professionals' representations of voice hearing groups. We surveyed 79 French health professionals using a questionnaire with 19 closed items. 7 additional items allowed us to specify the professional status and familiarity of the participants with the HVGs. Professionals generally shared positive representations of HVGs but had very approximate knowledge of them. The subgroup of the most familiar professionals (N = 45) differed significantly on 7 items from the subgroup of non-familiars (N = 35). HVGs are represented as one medical offer among others, of little clinical use and indicated only for psychotic voice-hearing patients, which seems to be a misunderstanding in every case. However, our study also shows that these opinions evolve with the degree of familiarity with HVGs. Certain representations need to be corrected so that quality information can be circulated about HVGs and improve their integration into their ecosystem.

Identification of Psychosis Risk and Diagnosis of First-Episode Psychosis: Advice for Clinicians

Early detection of psychotic-spectrum disorders among adolescents and young adults is crucial, as the initial years after psychotic symptom onset encompass a critical period in which psychosocial and pharmacological interventions are most effective. Moreover, clinicians and researchers in recent decades have thoroughly characterized psychosis-risk syndromes, in which youth are experiencing early warning signs indicative of heightened risk for developing a psychotic disorder. These insights have created opportunities for intervention even earlier in the illness course, ideally culminating in the prevention or mitigation of psychosis onset. However, identification and diagnosis of early signs of psychosis can be complex, as clinical presentations are heterogeneous, and psychotic symptoms exist on a continuum. When a young person presents to a clinic, it may be unclear whether they are experiencing common, mild psychotic-like symptoms, early warning signs of psychosis, overt psychotic symptoms, or symptoms better accounted for by a non-psychotic disorder. Therefore, the purpose of this review is to provide a framework for clinicians, including those who treat non-psychotic disorders and those in primary care settings, for guiding identification and diagnosis of early psychosis within the presenting clinic or via referral to a specialty clinic. We first provide descriptions and examples of first-episode psychosis (FEP) and psychosis-risk syndromes, as well as assessment tools used to diagnose these conditions. Next, we provide guidance as to the differential diagnosis of conditions which have phenotypic overlap with psychotic disorders, while considering the possibility of co-occurring symptoms in which case transdiagnostic treatments are encouraged. Finally, we conclude with an overview of early detection screening and outreach campaigns, which should be further optimized to reduce the duration of untreated psychosis among youth.

The "Hysterical Psychosis" Dilemma: A Narrative Review

BACKGROUND

Hysteria in its most severe expression may reach psychotic manifestations. Such symptomatology has been occasionally described by various authors starting from the 19th century and defined as "hysterical psychosis" (HP) by Hollender and Hirsch in 1964. Currently, diagnostic psychiatric manuals such as DSM and ICD do not include the diagnosis of HP, although this term is commonly used in clinical practice. This raises a well-known problem with case definition due to an inconsistent use of terminology.

SUMMARY

Here, we propose a review of the literature that aims to highlight the clinical features of HP endorsed by the majority of authors, such as histrionic premorbid personality, acute reactive onset, short duration, altered state of consciousness, unstable delusions, typical hallucinations, labile mood, lack of flat affect. In the discussion, we focus on the differential diagnosis between HP and other diagnoses such as brief psychosis and schizophrenia, trying to point out aspects of distinction and continuity.

KEY MESSAGES

The debate about this nosographic entity still remains a huge dilemma and needs further contributions.

Undiagnosing St Joan: She Does Not Need a Medical or Psychiatric Diagnosis

ABSTRACT

This article traces the history of Joan of Arc through her brief life that includes leading an army in defense of France at the age of 17 and ending with her death at the stake at the age of 19. In her activities, St Joan reported that she was guided by voices and visions in which she communicated with venerated spiritual figures such as St Michael and St Margaret. Questions have arisen about the nature of these experiences, and various medical and psychiatric diagnoses have been offered by contemporary experts. In our effort to evaluate the diagnostic proposals, we have examined the incidence of voices and visions in the Middle Ages, and we have followed that with a review of nonpathologic voice-hearing in our own era. We then move on to an analysis of some proposed medical and psychiatric diagnoses, all of which we find unconvincing. With this background, we argue that St Joan does not warrant a medical or psychiatric diagnosis. Such a conclusion, however, leaves us with another issue, that of Joan's achievements. How do we understand an adolescent being able to lead an army? Addressing this question proves more difficult than deciding whether St Joan warrants a diagnosis. In addition to her achievements in the war against Britain, Joan of Arc stands out as both the most documented person in Western civilization up until her era, and as the only person who has been both condemned and canonized by the Catholic Church.

Premorbid characteristics of patients with DSM-IV psychotic disorders

INTRODUCTION

Psychotic disorder not otherwise specified (PNOS) is considered part of the psychosis spectrum, together with schizophrenia spectrum disorders (SSD) and psychotic bipolar spectrum disorders (PBD). The atypical clinical presentations of PNOS conditions may lead to uncertainty regarding treatment choices and expected outcomes. PNOS is understudied, and little is known about patients' premorbid characteristics including premorbid adjustment, prevalence of early cannabis use and childhood trauma. Knowledge about early illness phases can increase our understanding of this diagnostic group.

METHODS

We included 1099 participants from the Norwegian TOP-study; 688 with narrow SSD diagnoses (schizophrenia, schizoaffective disorder, schizophreniform disorder), 274 with PBD (psychotic bipolar 1 and bipolar NOS) and 137 with PNOS diagnosed with the SCID-I for DSM-IV. Participants were assessed with the Premorbid Adjustment Scale (PAS) divided into the areas of premorbid academic and social functioning. We obtained information on age at first exposure to cannabis and use of cannabis before the age of 16. The participants also provided information regarding early traumatic experiences using the Childhood Trauma Questionnaire (CTQ).

RESULTS

Participants with PNOS and SSD had poorer premorbid academic functioning than those with PBD (F_{2, 1029} = 7.81, p < 0.001, _pη² = 0.015). Premorbid social adjustment was significantly worse in the SSD group compared to the PBD group (F_{2, 1024} = 3.10, p = 0.045, _pη² = 0.006), with PNOS in the middle position. Significantly more of the participants with PNOS (17.5%) and SSD (11.5%) used cannabis before the age of 16 compared with PBD (5.3%, Wald χ² = 6.86, p = 0.03). There were no significant differences between the three groups regarding mean CTQ scores or in the proportion of participants who had experienced at least one type of childhood adversity.

CONCLUSIONS

Participants with PNOS appear as more similar to participants with SSD than to those with PBD regarding early premorbid adjustment and early cannabis use. The results indicate that many conditions classified as PNOS have functional impairments and problematic substance use from an early age. The prevalence of childhood adversities are high in all three groups.

Malingering of Psychotic Symptoms in Psychiatric Settings: Theoretical Aspects and Clinical Considerations

Malingering is the intentional production of false or grossly exaggerated physical or psychological symptoms motivated by external incentives. Although the Diagnostic and Statistical Manual of Mental Disorders (DSM–5) does not list malingering in its diagnostic section and therefore does not identify it as a formal mental disorder, malingering and verified mental illness commonly coexist. Some subtypes of feigning behaviors, such as partial or pure malingering, dissimulation, and false imputation, can be suspected when patients have marked discrepancies between reported stressors and objective findings. The article discusses these three theoretical concepts with their possible clinical aspects, illustrating each phenomenon by clinical case with self-reported and/or observed psychotic symptoms. We summarized relevant findings and provided a review of clinical considerations that physicians can use to aid in the evaluation of psychotic symptoms in the context of those three concepts.

Auditory hallucinations across the psychosis spectrum: Evidence of dysconnectivity involving cerebellar and temporal lobe regions

BACKGROUND

Auditory hallucinations (AH) are typically associated with schizophrenia (SZ), but they are also prevalent in bipolar disorder (BD). Despite the large body of research on the neural correlates of AH in SZ, the pathophysiology underlying AH remains unclear. Few studies have examined the neural substrates associated with propensity for AH in BD. Investigating AH across the psychosis spectrum has the potential to inform about the neural signature associated with the trait of AH, irrespective of psychiatric diagnosis.

METHODS

We compared resting state functional magnetic resonance imaging data in psychosis patients with (n = 90 AH; 68 SZ, 22 BD) and without (n = 55 NAH; 16 SZ, 39 BD) lifetime AH. We performed region of interest (ROI)-to-ROI functional connectivity (FC) analysis using 91 cortical, 15 subcortical, and 26 cerebellar atlas-defined regions. The primary aim was to identify FC differences between patients with and without lifetime AH. We secondarily examined differences between AH and NAH within each diagnosis.

RESULTS

Compared to the NAH group, patients with AH showed higher FC between cerebellum and frontal (left precentral gyrus), temporal [right middle temporal gyrus (MTG), left inferior temporal gyrus (ITG), left temporal fusiform gyrus)], parietal (bilateral superior parietal lobules), and subcortical (left accumbens, left palldium) brain areas. AH also showed lower FC between temporal lobe regions (between right ITG and right MTG and bilateral superior temporal gyri) relative to NAH.

CONCLUSIONS

Our findings suggest that dysconnectivity involving the cerebellum and temporal lobe regions may be common neurofunctional elements associated with AH propensity across the psychosis spectrum. We also found dysconnectivity patterns that were unique to lifetime AH within SZ or bipolar psychosis, suggesting both common and distinct mechanisms underlying AH pathophysiology in these disorders.

What is a mental disorder? An exemplar-focused approach

The question of 'what is a mental disorder?' is central to the philosophy of psychiatry, and has crucial practical implications for psychiatric nosology. Rather than approaching the problem in terms of abstractions, we review a series of exemplars - real-world examples of problematic cases that emerged during work on and immediately after DSM-5, with the aim of developing practical guidelines for addressing future proposals. We consider cases where (1) there is harm but no clear dysfunction, (2) there is dysfunction but no clear harm, and (3) there is possible dysfunction and/or harm, but this is controversial for various reasons. We found no specific criteria to determine whether future proposals for new entities should be accepted or rejected; any such proposal will need to be assessed on its particular merits, using practical judgment. Nevertheless, several suggestions for the field emerged. First, while harm is useful for defining mental disorder, some proposed entities may require careful consideration of individual v. societal harm, as well as of societal accommodation. Second, while dysfunction is useful for defining mental disorder, the field would benefit from more sharply defined indicators of dysfunction. Third, it would be useful to incorporate evidence of diagnostic validity and clinical utility into the definition of mental disorder, and to further clarify the type and extent of data needed to support such judgments.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

Assessing Voice Hearing in Trauma Spectrum Disorders: A Comparison of Two Measures and a Review of the Literature

Voice hearing (VH) can occur in trauma spectrum disorders (TSD) such as posttraumatic stress disorder (PTSD) and dissociative disorders. However, previous estimates of VH among individuals with TSD vary widely. In this study, we sought to better characterize the rate and phenomenology of VH in a sample of 70 women with TSD related to childhood abuse who were receiving care in a specialized trauma program. We compared the rate of VH within our sample using two different measures: 1) the auditory hallucination (AH) item in the Structured Clinical Interview for DSM-IV-TR (SCID), and 2) the thirteen questions involving VH in the Multidimensional Inventory of Dissociation (MID), a self-report questionnaire that comprehensively assesses pathological dissociation. We found that 45.7% of our sample met threshold for SCID AH, while 91.4% met criteria for MID VH. Receiver operating characteristics (ROC) analyses showed that while SCID AH and MID VH items have greater than chance agreement, the strength of agreement is only moderate, suggesting that SCID and MID VH items measure related but not identical constructs. Thirty-two patients met criteria for both SCID AH and at least one MID VH item ("unequivocal VH"), 32 for at least one MID VH item but not SCID AH ("ambiguous VH"), and 6 met criteria for neither ("unequivocal non-VH"). Relative to the ambiguous VH group, the unequivocal VH group had higher dissociation scores for child voices, and higher mean frequencies for child voices and Schneiderian voices. Our findings suggest that VH in women with TSD related to childhood abuse is common, but that the rate of VH depends on how the question is asked. We review prior studies examining AH and/or VH in TSD, focusing on the measures used to ascertain these experiences, and conclude that our two estimates are consistent with previous studies that used comparable instruments and patient samples. Our results add to growing evidence that VH-an experience typically considered psychotic or psychotic-like-is not equivalent to having a psychotic disorder. Instruments that assess VH apart from psychotic disorders and that capture their multidimensional nature may improve identification of VH, especially among patients with non-psychotic disorders.

The Phenomenon of "Hearing Voices": Not Just Psychotic Hallucinations-A Psychological Literature Review and a Reflection on Clinical and Social Health

The phenomenon of hearing voices is currently a much-discussed topic, both in the field of research and in the field of care services. The majority of people who report "hearing voices" do not subsequently receive services or receive a diagnosis of psychopathology. This topic raises questions for professionals in the health field about the lack of tools that can help illuminate the phenomenon. The purposes of this work are (a) to highlight the psychological studies that approach the phenomenon in a non-psychopathological way and (b) to determine which concepts could aid the comprehension of the phenomenon. The method consists of a systematic review of the literature that characterizes the phenomenon of hearing voices from a non-pathological perspective. The literature offers different theoretical approaches to interpret the phenomenon in a way that is not necessarily pathological and presents new tools for examining the phenomenon. For example, a few studies state that it is possible to coexist with voices, while others indicate that it is necessary to know how to manage voices. We highlighted and discussed several concepts that can support doctors, psychiatrists and practitioners in understanding "hearer" patients, particularly attention to the context of belonging, attention to language, and the role of the sense-making process.

Minor Hallucinations in Alzheimer's Disease

BACKGROUND

Hallucinations may have a broad spectrum and include so-called minor hallucinations (MHs). MHs include passage hallucinations (PHs), visual illusions, and presence hallucinations (PrHs).

OBJECTIVE

To determine the prevalence and characteristics of MHs in Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) patients, and to describe their potential relationship with cognition, behavioral symptoms, and use of psychoactive drugs.

METHODS

We have recruited prospectively and consecutively 268 subjects (90 AD mild-moderate drug-naïve patients, 78 aMCI, and 100 controls). All patients responded to a semi-structured questionnaire in order to rate psychotic phenomena. Clinical, neuropsychological, and demographic data of patients with and without MH were compared with those of age, sex, and education-matched controls.

RESULTS

The prevalence of MHs was 21.1% (19) in AD, 12.8% (10) in aMCI, and 3% (3) in controls (p < 0.01). The most frequent MH was PrH (9.3%), followed by PH (4.9%) and illusion (0.7%). Eight (27.8%) patients had more than one MH. After adjusting for age and gender, there was a negative correlation between the presence of MHs and MMSE score (r = -0.261; p < 0.01) and a positive correlation between MHs and Neuropsychiatric Inventory score (r = 0.237; p < 0.01). We did not observe a significant relationship between presence of MHs and the consumption of psychoactive drugs (p > 0.05).

CONCLUSION

We have shown that the presence of MHs in patients with newly diagnosed, untreated AD and aMCI is more than controls. MHs were correlated with other behavioral symptoms and a worse cognitive performance. We suggest the specific interrogation for MHs as a clinical feature for this population.

Auditory hallucinations and PTSD in ex-POWS

Literature has suggested that auditory hallucinations might be prevalent in the general population and could be linked to the experience of trauma. This prospective study examines the prevalence of auditory hallucinations in trauma survivors and its association with posttraumatic stress disorder (PTSD) symptoms, over time. Former prisoners of war (ex-POWs) from the 1973 Yom Kippur War (n = 99) with and without PTSD and comparable veterans (n = 103) were assessed twice, in 1991 (T1) and 2003 (T2) in regard to auditory hallucinations and PTSD symptoms. Findings indicated that ex-POWs who suffered from PTSD reported higher levels of auditory hallucinations at T2 as well as increased hallucinations over time, compared to ex-POWs without PTSD and combatants who did not endure captivity. The relation between PTSD and auditory hallucinations was unidirectional, so that the PTSD overall score at T1 predicted an increase in auditory hallucinations between T1 and T2, but not vice versa. Assessing the role of PTSD clusters in predicting hallucinations revealed that intrusion symptoms had a unique contribution, compared to avoidance and hyperarousal symptoms. The findings suggest that auditory hallucinations might be a consequence of the posttraumatic reaction among veterans.

Screening for sub-threshold psychotic experiences and perceived need for psychological services

AIM

Sub-threshold psychotic experiences (PEs) are common in the general population and may increase risk for psychological distress and psychosis onset, generating a need for effective community screening instruments. This study aimed to explore the utility of a brief, self-report, psychosis risk screening tool in predicting perceived need for psychological treatment among a non-clinical sample, above and beyond that accounted for by accompanying forms of psychopathology or trait neuroticism.

METHODS

Construct validity, predictive validity and test-retest reliability of the brief, self-report questionnaire for screening putative prepsychotic states were determined among college students (N = 679). Multiple linear regression analyses were conducted to explore the relationship between PEs and perceived need for psychological services.

RESULTS

With the exception of auditory perceptual disturbances, PEs were not significantly associated with one's need for services, or the belief from others that services are needed, after controlling for neuroticism, anxiety and depressive symptoms. Auditory perceptual disturbances were significantly associated with the perceived need for psychological services, even after accounting for these additional symptoms.

CONCLUSIONS

These results confirm the usefulness of the psychosis risk screening tool in evaluating the presence of sub-threshold PEs, particularly auditory perceptual disturbances. The relationship between other PEs and a perceived need for psychological services, however, was largely explained by the existence of neurotic traits and anxiety and depressive symptoms. Screening for auditory perceptual disturbances may be useful in identifying unmet clinical need among young adults.

The prevalence and characteristics of hallucinations, delusions and minor phenomena in a non-demented population sample aged 60 years and over

OBJECTIVE

Psychotic phenomena can occur in non-clinical subjects. The goals of this study were to assess the prevalence of delusions, hallucinations and minor 'psychotic' phenomena (visual illusions, feeling of presence and passage hallucinations) and to describe the characteristics of the latter in a non-clinical older population.

METHODS

Three hundred and thirteen individuals aged 60 years and older, without cognitive deficits (according to mini-mental state examination scores) or patent psychotic disease, answered a structured questionnaire focusing on delusions, hallucinations and minor phenomena that they had experienced in the previous month. The study sample was stratified by age and gender according to French demographic characteristics.

RESULTS

Twenty per cent of participants reported one or more psychotic phenomena. These subjects did not differ from those without psychotic symptoms as regards their age, mini-mental state examination scores or education. Minor phenomena were the most common (13%). Hallucinations, in any sensory modality, occurred in 9% of participants. No verbal auditory hallucinations or delusions were reported. The prevalence of minor phenomena increased with age and was associated with the use of psychoactive drugs.

CONCLUSION

By extending the spectrum of psychotic symptoms to minor phenomena, we found that psychotic symptoms were common in a non-clinical older population. Whether the increasing prevalence of minor phenomena with age is due to prodromal neurodegenerative disease or to other factors remains to be investigated. Copyright © 2016 John Wiley & Sons, Ltd.

Prayer Camps and Biomedical Care in Ghana: Is Collaboration in Mental Health Care Possible?

Background

Experts have suggested that intersectoral partnerships between prayer camps and biomedical care providers may be an effective strategy to address the overwhelming shortage of mental health care workers in Africa and other low-income settings. Nevertheless, previous studies have not explored whether the prayer camp and biomedical staff beliefs and practices provide sufficient common ground to enable cooperative relationships. Therefore, we sought to examine the beliefs and practices of prayer camp staff and the perspective of biomedical care providers, with the goal of characterizing interest in—and potential for—intersectoral partnership between prayer camp staff and biomedical care providers.

Methods

We conducted 50 open-ended, semi-structured interviews with prophets and staff at nine Christian prayer camps in Ghana, and with staff within Ghana’s three public psychiatric hospitals. We used the purposive sampling method to recruit participants and the constant comparative method for qualitative data analysis.

Results

Prayer camp staff expressed interest in collaboration with biomedical mental health care providers, particularly if partnerships could provide technical support introducing medications in the prayer camp and address key shortcomings in their infrastructure and hygienic conditions. Nevertheless, challenges for collaboration were apparent as prayer camp staff expressed strong beliefs in a spiritual rather than biomedical explanatory model for mental illness, frequently used fasting and chained restraints in the course of treatment, and endorsed only short-term use of medication to treat mental illness—expressing concerns that long-term medication regimens masked underlying spiritual causes of illness. Biomedical providers were skeptical about the spiritual interpretations of mental illness held by faith healers, and were concerned by the use of chains, fasting, and the lack of adequate living facilities for patients in prayer camps; many, however, expressed interest in engaging with prayer camps to expand access to clinical care for patients residing in the camps.

Conclusions

The findings demonstrate that biomedical care providers are interested in engaging with prayer camps. Key areas where partnerships may best improve conditions for patients at prayer camps include collaborating on creating safe and secure physical spaces and delivering medication for mental illness to patients living in prayer camps. However, while prayer camp staff are willing to engage biomedical knowledge, deeply held beliefs and routine practices of faith and biomedical healers are difficult to reconcile Additional discussion is needed to find the common ground on which the scarce resources for mental health care in Ghana can collaborate most effectively.

Understanding auditory verbal hallucinations: a systematic review of current evidence

OBJECTIVE

Auditory verbal hallucinations (AVHs) are core features of psychotic illness and remain significant in predicting poor outcome and risk. There has been a wide range of approaches to understanding these experiences.

METHOD

A systematic literature review summarizing different methods of investigation and their results; phenomenology, descriptive psychopathology, psychological, cognitive neurobiology, and neuroimaging.

RESULTS

A number of 764 papers and texts were screened and 113 reviewed. Phenomenological studies are comparably few in number, and psychopathology remains based on concepts defined in the early 20th century. Psychological models focus on voice content and emotional reaction, and suggest a continuum of AVHs from normal experience. Neuropsychological models include AVHs as misattribution of inner speech, whilst functional neuroimaging studies focus on the spontaneous activity and connectivity of auditory networks.

CONCLUSION

There has been a large growth in research on AVHs in recent decades dominated by neurobiological and neuroimaging studies. Future research should include focus on phenomenological aspects and AVHs change over the course of developing illness. Integration between branches of enquiry is needed, and the risk is that without this, models are proposed and investigated that bear scant relevance to the symptom itself.

Unusual perceptions at the end of life: limitations to the diagnosis of hallucinations in palliative medicine

The diagnosis of hallucination for unusual perceptions such as deathbed visions, near-death experiences, or visions of the bereaved, is unhelpful in palliative medicine both academically and clinically. This paper reviews the broad prevalence data about unusual perceptions in the general population as background to identifying the more narrow epidemiological source from which the much smaller focus on hallucinations seem to emerge. Major debates and limitations of current hallucination research are reviewed to show that current academic and clinical certainties are largely confined to unusual perceptions that can be readily linked to psychopathology, quite specific organic disease states and psychoactive drug use. Current state-of-the-art in hallucination studies does not warrant broad or uncritical use of this type of diagnosis in end-of-life care. Conclusions from interdisciplinary (as opposed to single discipline) hallucination studies suggest that the way forward for clinical and research work in palliative medicine may lie in a more biographical and cultural approach to unusual perceptions at the end of life.

Increased risk of psychosis in patients with hearing impairment: Review and meta-analyses

Several studies suggest hearing impairment as a risk factor for psychosis. Hearing impairment is highly prevalent and potentially reversible, as it can be easily diagnosed and sometimes improved. Insight in the association between hearing impairment and psychosis can therefore contribute to prevention of psychosis. This paper provides meta-analyses of all epidemiologic evidence on the association between hearing impairment and psychosis and summarizes mechanisms that potentially underlie this relationship. Meta-analyses showed an increased risk of hearing impairment on all psychosis outcomes, such as hallucinations (OR 1.40(95%CI 1.18-1.65; n=227,005)), delusions (OR 1.55(95%CI 1.36-1.78; n=250,470)), psychotic symptoms (OR 2.23(95%CI 1.83-2.72; n=229,647) and delirium (OR 2.67(95%CI 2.05-3.48; n=12,432). Early exposure to hearing impairment elevated the risk of later development of schizophrenia (OR 3.15(95%CI 1.25-7.95; n=50,490)). Potential mechanisms underlying this association include loneliness, diminished theory of mind, disturbances of source monitoring and top-down processing and deafferentiation. Early assessment and treatment of hearing impairment in patients with (high risk of) psychosis may be essential in psychosis treatment and prevention.

Post-bereavement hallucinatory experiences: A critical overview of population and clinical studies

BACKGROUND

Removal of the "bereavement exclusion" criterion for major depression and proposed research criteria for persistent complex bereavement disorder in DSM-V pose new compelling issues regarding the adequacy of current nosographical boundaries. Post-bereavement hallucinatory experiences (PBHE) are abnormal sensory experiences that are frequently reported by bereaved individuals without a history of mental disorder. Given current uncertainty over the continuum of psychotic experiences in the general population, whether or not they should be considered pathological remains unclear.

METHODS

In order to systemize available knowledge, we reviewed the literature describing general population and clinical studies on PBHEs. Given the relatively low number of articles, all peer-reviewed, published studies in English were included. No study characteristics or publication date restrictions were imposed.

RESULTS

Overall, evidence suggests a strikingly high prevalence of PBHEs - ranging from 30% to 60% - among widowed subjects, giving consistence and legitimacy to these phenomena.

LIMITATIONS

Whereas general population studies had adequate sample size numbers, all studies in the bereaved population had a very small number of subjects. No consensus for method of evaluation exists in the literature, with some studies using a free interview method and others using semi-structured interviews.

CONCLUSIONS

The available literature appears to support an elevated frequency of PBHEs in bereaved individuals, but further research is needed to increase the reliability of these findings and refine the boundaries between physiological and pathological experiences.

Prevalence of auditory verbal hallucinations in a general population: A group comparison study

The present study was specifically designed to investigate the prevalence of auditory verbal hallucinations (AVH) in the general population, and sought to compare similarities and differences regarding socio-demographics, mental health and severe life events between individuals who have never experienced AVH with those who had. The study also aimed to compare those who sought professional help for their experience of AVH with those who had not sought help. Through a postal questionnaire, 2,533 participants ages 18 and over from a national survey completed the Launay-Slade Hallucinations Scale and other measures examining AVH characteristics and other areas related to AVH. In total, 7.3% of the sample reported a life-time prevalence of AVH. Those with AVH were more likely to be single and unemployed, reported higher levels of depression and anxiety, and experienced a higher number of severe life events compared with those without AVH. Only 16% of those who experienced AVH in the general population sought professional help for these experiences. Compared to those who did not seek professional help, participants that had were more likely to experience AVH with a negative content, experience them on a daily basis, undergo negative reactions when experiencing AVH, and resist AVH. In conclusion, the prevalence of AVH was found to be relatively high. The results also revealed higher levels of reduced mental health for individuals who sought professional help, followed by those who did not, compared with those who had never experienced AVH.

Psychometric properties of the Posttraumatic Cognition Inventory within a Northern Ireland adolescent sample

OBJECTIVES

This study sought to investigate the psychometric properties of the Posttraumatic Cognitions Inventory (PTCI; Foa et al., 1999, Psychol. Assess., 11, 303) among a cohort of older adolescents and to determine the relationship between post-traumatic cognitions and a variety of psychological outcomes including depression, anxiety, stress, and loneliness.

METHODS

The PTCI was investigated among a large sample (N = 785) of Northern Irish adolescents. Confirmatory factor analysis and composite reliability analysis were conducted to assess the psychometric properties of the scale.

RESULTS

The familiar three-factor solution of negative cognitions of self, negative cognitions of the world and others, and self-blame was supported; however, it was necessary to remove eight items from the original 33-item scale. The three-factor structure was subsequently demonstrated to be factorially invariant across gender and to possess satisfactory internal reliability. The three PTCI factors were found to correlate with depression, anxiety, stress, and three dimensions of loneliness.

CONCLUSION

These results provide the first piece of evidence that older adolescents cognitively respond to trauma in a similar manner to adults, that the PTCI is factorially invariant between genders, and that trauma cognitions are correlated with feelings of loneliness. The contextual dependent nature of the structure of the PTCI factors is discussed in relation to future research efforts.

PRACTITIONER POINTS

The PTCI is a valid and reliable measure of trauma-related cognitions among adolescents and works equally well for male adolescents and female adolescents. Trauma cognitions are associated with a range of mental health problems beyond post-traumatic stress disorder including depression, anxiety, stress, and various aspects of loneliness. Reductions in trauma cognitions in survivors of trauma will have wide-scale clinical benefits to patient well-being. The exact structure and make-up of items in the PTCI may well be dependent on culture, context, and the nature of the trauma. The study is limited due to the fact that the authors could not assess the severity of the trauma experienced by the adolescent sample.

Distinguishing schizophrenia from posttraumatic stress disorder with psychosis

PURPOSE OF REVIEW

Co-occurrence of psychotic symptoms with symptoms typically thought of as posttraumatic stress disorder (PTSD) is well known, and there has been considerable debate whether this represents a psychotic subtype or a comorbid psychotic disorder.

RECENT FINDINGS

Psychotic symptoms typical of schizophrenia occur with a higher than expected frequency in PTSD. A large genome-wide association study (GWAS) has identified a collection of genes associated with PTSD, and these genes overlap with those identified as increasing the risk of developing schizophrenia.

SUMMARY

Up to 70% of returning veterans experience symptoms of PTSD. These individuals also fall within the peak age range for the onset of schizophrenia. PTSD with psychosis may occur for several reasons: trauma increases one's risk for schizophrenia and PTSD; patients with schizophrenia have a higher incidence of PTSD and may present with characteristic psychotic symptoms overlapping with psychosis in schizophrenia. Secondary to symptom overlap, there may be substantial misdiagnosis of psychotic disorders as PTSD, or nonidentification of a comorbid psychotic disorder. This overlap calls into question traditional diagnostic boundaries with implications for initial and long-term treatment of PTSD and psychosis. This review will discuss the recent literature relating to the association of PTSD with schizophrenia.

Differences in the internal structure of hallucinatory experiences between clinical and nonclinical populations

We investigated differential patterns of hallucinatory experiences between nonclinical and clinical samples. A total of 223 nonclinical individuals (108 females) and 111 subjects with schizophrenia (54 females) completed the Launay-Slade Hallucination Scale-Revised (LSHS-R) and Perceptual Aberration Scale (PAS). The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) was used for the nonclinical group, and the Positive and Negative Syndrome Scale (PANSS) hallucination item was used for the clinical group. Cronbach's alpha values showed good internal consistency for the LSHS-R. In the two groups, significant associations were found between LSHS-R and PAS scores. Two factors were extracted through a principal component analysis (PCA) in the nonclinical group, and three factors were identified in the clinical group. The results of a hierarchical cluster analysis (HCA) revealed that a perception-cognition dimension was clear cluster discriminating element for the nonclinical group, whereas alterations in perception-cognition dimension were characteristic in cluster structure of the clinical group. Our findings suggest that the nature of hallucinatory experiences may differ qualitatively between a nonclinical population and subjects with schizophrenia. Perceptual or cognitive aberrations may add a psychopathologic dimension to hallucinatory experiences. Exploring the internal structure of hallucinatory experiences may provide explanatory insight into these experiences in the general population.

Depictions of auditory verbal hallucinations in news media

BACKGROUND

The characterization of auditory verbal hallucinations (AVH) in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V), diverges from recent research literature, which demonstrates the occurrence of AVH in individuals who are psychologically healthy. This discrepancy raises the question of how the public perceives AVH. Public perceptions are important because they could potentially affect how individuals with AVH interpret these experiences and how people view voice hearers.

AIMS

Because media portrayals can provide a window into how phenomena are viewed by the public, an archival study of newspaper articles was carried out to examine depictions of AVH.

METHODS

A sample of 181 newspaper articles originating in the United States was analyzed using a content analysis approach.

RESULTS

The majority of articles examined contained no suggestion that AVH are possible in psychologically healthy individuals. Most articles suggested that AVH were a symptom of mental illness, and many suggested that AVH were associated with criminal behavior, violence and suicidality.

CONCLUSION

The news media examined tended to present a misleading and largely pathologizing view of AVH. More research is needed to shed light on how, and to what extent, public perceptions may influence those who experience AVH.

History and conceptual problems of the relationship between obsessions and hallucinations

Contemporary psychiatric nomenclature defines schizophrenia (SCZ) and obsessive-compulsive disorder (OCD) as distinct disease entities characterized by non-overlapping diagnostic criteria. Nevertheless, a complex association between SCZ and OCD exists on the psychopathological level. And although the relationship between obsessions and delusions has been widely studied and discussed, the relationship between obsessions and hallucinations has not received the same attention. This article presents an historical overview of the studies on the co-occurrence of obsessions and hallucinations. We also analyze the clinical significance of this overlap, as discussed in the early descriptions of these phenomena in the nineteenth century and continuing through the most recent, contemporary conceptualizations. In clinical practice today, we may encounter both SCZ patients with typical ego-dystonic obsessive-compulsive symptoms and SCZ patients affected by obsessions that intertwine with psychotic symptoms, generating complex psychopathological syndromes (e.g. "obsessive hallucinations"). A further complication is that some OCD patients show perceptual disturbances. Taking into consideration the possible coexistence of obsessive-compulsive symptoms and psychotic symptoms is crucial for proper diagnosis, prognosis, and treatment. Further investigations are required to fully evaluate the psychopathological interrelationships between obsessions and hallucinations.

The experience of engaging with mental health services among young people who hear voices and their families: a mixed methods exploratory study

Background

Research shows us that auditory hallucinations or ‘hearing voices’ may be more common than previously thought, particularly in childhood and adolescents. Importantly, not all individuals are affected negatively by their voice hearing experiences, yet child and adolescent mental health services (CAMHS) have traditionally understood voice hearing as a symptom of psychosis and severe mental illness, with implications for the way interventions are offered. The purpose of the present study was to gain an understanding of how young people who hear voices and their families find engaging with mental health service, and to better understand their experience of mental health professionals.

Methods

A two-stage, mixed methods study was used. In the first stage, semi-structured interviews were carried out with two young people and their parents who had engaged with mental health services, and the collected data were analysed using Interpretative Phenomenological Analysis (IPA). In the second stage, a questionnaire was designed to test the generalizability of the themes arising from the first stage, and was completed online by 32 young voice hearers and 27 parents.

Results

IPA analysis produced 4 themes: (1) The struggle to understand the hearing voices phenomenon; (2) Battle with the Mental Health Services; (3) ‘Stuck in a limbo’; and (4) The wish for a more holistic approach from mental health services and professionals. The survey partially confirmed the findings of study one, with young people and parents finding useful information difficult to come by, and many reported feeling lost in CAMHS. Additionally, young voice hearers and parents often felt not listened to, and many parents expressed the need for a holistic care, whilst young people wanted a more normalizing and less stigmatizing experience.

Conclusions

Young people and their families had varying experiences of mental health services. Whilst the survey showed that some young people and their families had more positive experiences, many expressed dissatisfaction. To fulfil the needs of young people and their families, mental health services would benefit from developing alternative approaches to voice hearing and running support groups that could form part of a ‘normalising’ and ‘holistic care’ package.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-014-0527-z) contains supplementary material, which is available to authorized users.

[Hallucinations and borderline personality disorder: a review]

INTRODUCTION

Hallucinations constitute understudied symptoms in borderline personality disorders (BPD), which can be observed in about 30% of the patients, essentially in the auditory modality. Most of these experiences are transitory, triggered by intermittent stressors, but chronicity remains a major cause of concern. In order to better circumscribe hallucinations in BPD, we summarized the literature on this particular phenomenon.

METHODS

We conducted a review using Medline, Scopus and Google Scholar databases up to March 2013, using the following keywords combinations: "borderline personality disorder", "hallucinat*" and "psychotic symptoms". Papers were included in the review if they were published in an English or French language peer-reviewed journal; the study enrolled patients with BPD; and the diagnosis was made according to the Diagnostic and Statistical Manual (DSM) criteria. Fifteen studies published between 1985 and 2012, merging a total of 635 patients, were retained.

RESULTS

The hallucinatory experiences observed in BPD appeared phenomenologically similar to those described in the schizophrenia spectrum in terms of vividness, duration, spatial localization, beliefs about malevolence or omnipotence. Conversely, the hallucinatory content appeared more negative and potentially more distressful. Crucially, this literature search also revealed that these symptoms have long been regarded as "pseudo-hallucinations" (or "hallucination-like symptoms"). This concept was judged of poor scientific validity, inducing stigma for BPD patients in that it casts doubt on the authenticity of these experiences while disqualifying the related distress. This situation points out that research should focus more on understanding hallucinations in BPD than questioning their existence. Interestingly, recent comorbidity studies reopened a 40-year debate on the potential links that may exist between BPD and psychosis. Initially considered as a para-psychotic disorder, BPD was effectively redefined as an independent category by Otto F. Kernberg, leading to the DSM-III definition, excluding any psychotic symptom. However, hallucinations per se remain insufficient to diagnose schizophrenia, while comorbid substance use disorders as well as mood disorders, cannot explain all the hallucination occurrences in BPD. By referring to the "psychotic-reactivity-to-stress" framework, we proposed to understand hallucinations in BPD in relation to a hyperactivity of the hypothalamic-pituitary-adrenal axis and of the dopaminergic system under stress. Childhood trauma may have a central role in such a model. The prevalence of childhood trauma is high in BPD but this factor was also evidenced strongly linked with hallucinations in non-clinical populations. Comparisons are finally made and discussed between hallucinations occurring in BPD and those observed in posttraumatic stress disorder, another frequent comorbid disorder.

CONCLUSION

Almost a third of patients with BPD experiences hallucinations, and future studies will have to clarify the pathophysiology of this symptom, still poorly understood. Both the models of psychotic-reactivity-to-stress, as well as the role of childhood trauma in the context of a gene X environment interaction, appear to be promising cues for future research.

Psychotic-like experiences, symptom expression, and cognitive performance in combat veterans with posttraumatic stress disorder

Apparent psychotic symptoms are often associated with posttraumatic stress disorder (PTSD), but these symptoms are poorly understood. In a sample of 30 male Vietnam combat veterans with severe and chronic PTSD, we conducted detailed assessments of psychotic symptom endorsement, insight, symptom severity, neurocognitive function, and feigning. Two thirds of the subjects endorsed a psychotic item but did not believe that the experiences were real. Those endorsing psychotic items were higher in PTSD severity, general psychopathology, and dissociation but not depression, functional health, cognitive function, or feigned effort. Severity of psychotic symptoms correlated with dissociation, combat exposure, and attention but not PTSD, depression, or functional health. Those endorsing psychotic items scored higher on a screen but not on a detailed structured interview for malingering. Endorsement of psychotic experiences by combat veterans with PTSD do not seem to reflect psychotic symptoms or outright malingering.

Phantabulation: a case of visual imagery interference on visual perception

We report the case of a 52-year old man who, following rupture of an anterior communicating artery aneurysm, presented with a phenomenon not previously described, which we have labelled "Phantabulation." Phantabulation is characterized by frequent and purposeful interactions with contextually appropriate imagined objects. We suggest that this phenomenon results from confusion between real and imagined objects, caused by failure to inhibit florid visual imagery, facilitated by cortical release mechanisms.

Understanding the experiences of hearing voices and sounds others do not hear

In this article, we aim to contribute to the understanding of how people with mental illness experience hearing voices and sounds that others do not hear in daily life. We conducted in-depth interviews with 14 people and analyzed the interviews using a hermeneutic phenomenological approach. The themes we arrived at included the following: hearing someone else or myself, am I losing my mind?, and daily life recurrently dominated by opposing voices. Our overall understanding of how the voices and sounds were experienced in daily life was that the intentions of others resounded intrusively in the participants and disrupted their lives. The tones and contents of these perplexing perceptions echoed and amplified past, present, and future experiences and concerns. The results elucidate the value that exploring and attempting to understand people's daily life experiences of hearing voices and sounds might have for the voice hearer, his or her family, and health care providers.

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

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.

[Trauma and psychosis--part 2. On the association of early childhood maltreatment and risk of psychosis in general population]

Any association of early childhood maltreatment and later risk of psychosis may be favourably investigated by epidemiological studies in the general population. Primary outcome variable in these studies is the prevalence of subclinical psychotic symptoms (hallucinations, delusions) in early trauma-exposed groups compared to control groups without any significant trauma in childhood. A systematic literature search underlines a significant association of early childhood trauma and later non-clinical psychotic symptoms in representative samples of the general population both during childhood, adolescence and adulthood. Important questions deal with the issues, which psychological, psychosocial and neurobiological mechanisms may mediate the risk of early trauma in respect of later psychotic symptoms on the one side, and which factors may determine the transition from non-clinical psychotic symptoms to major psychotic disorders cared for within mental health services. Both theoretical models and first data derived from empirical studies will be presented.

Auditory hallucinations in a cross-diagnostic sample of psychotic disorder patients: a descriptive, cross-sectional study

BACKGROUND

Auditory hallucinations (AH) are a cardinal feature of schizophrenia spectrum disorders. They are not disease specific, however, and can occur in other conditions, including affective psychoses.

METHODS

In this descriptive, cross-sectional study, we examined AH in relation to other psychotic symptoms, mood symptoms, illness severity, and functional status in 569 patients with psychosis (n = 172 schizophrenia, n = 153 schizoaffective disorder, n = 244 bipolar disorder with psychotic features).

RESULTS

A total of 323 (56.7%) patients reported a lifetime history of AH (75.6% of patients with schizophrenia, 71.9% schizoaffective disorder, and 34.0% bipolar disorder). The mean score for the hallucinations item (P3) of the Positive and Negative Syndrome Scale in the AH group was 3.66 ± 1.79, indicating mild to moderate state hallucinations severity. Auditory hallucinations were strongly associated with hallucinations in other sensory modalities and with the first-rank symptoms of delusions of control, thought insertion, and thought broadcasting. Multivariate analysis showed that AH were associated with lower education even after controlling for diagnosis, age, and sex. There was no association between AH and functional status as measured by the Multnomah Community Ability Scale.

CONCLUSIONS

Auditory hallucinations are associated with specific clinical features across the continuum of both schizophrenic and affective psychoses independent of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis.

A survey of psychosis risk symptoms in Kenya

Defining the prepsychotic state in an effort to prevent illness progression and the development of disorders such as schizophrenia is a rapidly growing area of psychiatry. The presentation of psychotic symptoms can be influenced by culture; however, there has not been any previous assessment of psychosis risk symptoms in the continent of Africa. Our study aimed to measure the prevalence of psychosis risk in a community sample in Nairobi, Kenya, and to evaluate the effects of key demographic variables. A culturally modified version of the 12-item PRIME-Screen (mPRIME) was self-administered by 2758 youth (aged 14-29 years) recruited through house-to-house visits in Nairobi, Kenya. The prevalence and severity of psychosis risk items from the mPRIME and the effects of sex and age on symptoms were evaluated. k-Means cluster analysis was used to identify symptom groups. Depending on the mPRIME item, 1.8% to 19.5% of participants reported certainty of having had a psychosis risk symptom. Overall, 45.5% reported having had any psychosis risk symptom. Females had a significantly higher mean severity score on items evaluating persecutory ideation and auditory hallucinations. Symptom severity on 5 items showed a modest (R = 0.09-0.13) but significant correlation with age. Cluster analysis identified 4 groups of participants: normative (55%), high symptom (11%), intermediate symptom (19%), and grandiose symptom (15%). Psychosis risk symptoms appear to be highly prevalent in Kenyan youth. Longitudinal studies are needed to determine the correlation of identified symptoms with transition to psychotic illness, as well as the associated functionality and distress, to develop appropriate intervention strategies.

Prevalence and characteristics of psychotic-like experiences in Kenyan youth

Current evidence suggests that there may be significant differences in psychotic symptom prevalence in Africa compared with other cultures. However, there have been few studies evaluating these symptoms in the continent. We conducted a cross-sectional survey of psychotic-like experiences (PLEs) in 2963 Kenyan students from seven tertiary academic institutions spread across Kenya, using a self-administered psychosis questionnaire evaluating psychotic experiences and demographic variables. Logistic regression was used to evaluate relationship between PLEs and demographic variables. Latent class analysis (LCA) was used to determine specific classes of psychotic experiences. Twenty-three percent of respondents reported having at least one PLE, and 19% reported this unrelated to drug use or sleep. Compared to students identifying as Protestant Christians, Catholics had a lower likelihood of having any PLE or visual hallucinations. Other demographic variables were not significantly associated with PLEs. LCA of PLEs resulted in a three-class model that comprised 1) a non-psychotic class (83.8%), 2) a predominantly hallucinatory class ("type I PLE"; 12.7%), and 3) a multiple symptom class ("type II PLE"; 3.5%). Both psychotic classes had a predominance of male students. Further studies are required to clarify functionality and clinical progression associated with observed patterns of psychosis, as well as the generalizability of our findings.

Cognitive mechanisms of auditory verbal hallucinations in psychotic and non-psychotic groups

The continuum model of psychosis has been extremely influential. It assumes that psychotic symptoms, such as auditory verbal hallucinations (AVH), are not limited to patients with psychosis but also occur in healthy, non-clinical individuals - suggesting similar mechanisms of origin. Recent debate surrounding this model has highlighted certain differences, as well as similarities, in the phenomenology of AVH in clinical and non-clinical populations. These findings imply that there may, in fact, be only partial overlap of the mechanism(s) involved in generating AVH in these groups. We review evidence of continuity or similarity, and dissimilarity, in cognitive, and related neural processes, underlying AVH in clinical and non-clinical samples. The results reveal some shared (intrusive cognitions, inhibitory deficits) and some distinct (aspects of source memory and cerebral lateralization) mechanisms in these groups. The evidence, therefore, supports both continuous and categorical models of positive psychotic symptoms. The review considers potential risks of uncritical acceptance of the continuum model and highlights some important methodological issues for future research.

Evaluation of evidence for the psychotic subtyping of post-traumatic stress disorder

Psychotic symptoms may occur in 15-64% of individuals with post-traumatic stress disorder, suggesting that the syndrome could be subtyped in a similar fashion to mood disorders. In our study of 1800 psychiatric out-patients who completed comprehensive diagnostic interviews, the lifetime prevalence of psychotic symptoms in people with PTSD was 17% (odds ratio (OR) = 3.48, 95% CI 2.32-5.21). However, after excluding people with comorbid conditions also known to be associated with psychotic symptoms this dropped to only 2.5% (OR) = 0.60, 95% CI 0.08-4.52). In contrast, rates of psychotic major depression did not change after excluding these same comorbidities. Our results do not support the official psychotic subtyping of PTSD.