Hallucinations and related concepts-their conceptual background

Bridging flexible goal-directed cognition and consciousness: The Goal-Aligning Representation Internal Manipulation theory

Goal-directed manipulation of internal representations is a key element of human flexible behaviour, while consciousness is commonly associated with higher-order cognition and human flexibility. Current perspectives have only partially linked these processes, thus preventing a clear understanding of how they jointly generate flexible cognition and behaviour. Moreover, these limitations prevent an effective exploitation of this knowledge for technological scopes. We propose a new theoretical perspective that extends our 'three-component theory of flexible cognition' toward higher-order cognition and consciousness, based on the systematic integration of key concepts from Cognitive Neuroscience and AI/Robotics. The theory proposes that the function of conscious processes is to support the alignment of representations with multi-level goals. This higher alignment leads to more flexible and effective behaviours. We analyse here our previous model of goal-directed flexible cognition (validated with more than 20 human populations) as a starting GARIM-inspired model. By bridging the main theories of consciousness and goal-directed behaviour, the theory has relevant implications for scientific and technological fields. In particular, it contributes to developing new experimental tasks and interpreting clinical evidence. Finally, it indicates directions for improving machine learning and robotics systems and for informing real-world applications (e.g., in digital-twin healthcare and roboethics).

A systematic review and meta-analysis of synthetic cathinone use and psychosis

RATIONALE

Synthetic cathinones (SC), commonly referred to as "bath salts", are stimulants resembling the natural alkaloid cathinone found in the khat plant. These substances have the potential to induce serious health risks such as hallucinations, delusions, paranoia and agitation which can lead to substance-induced psychotic disorders. Despite growing concerns, there is a limited understanding of the association between SC consumption and the devolvement of such psychopathologies.

METHODS

We conducted a systematic review to investigate the frequency of substance-induced psychotic disorder (SIPD) and associated conditions in humans following synthetic cathinone consumption. We qualitatively and quantitatively analyzed SC exposure cases.

RESULTS

A total of 32 studies were included, with a diverse range of demographics, synthetic cathinone types, and consumption patterns. The proportion of individuals developing psychotic symptoms was reported at 0.380 (Random-effects model, 95% CI 0.289 - 0.475). Additionally, the significant heterogeneity in diagnostic approaches limited our ability to provide a precise estimate of prevalence.

CONCLUSIONS

Synthetic cathinone consumption is associated with the risk of developing psychotic symptoms as indicated by the prevalence of hallucinations and/or delusions. Due to the lack of information on classifying factors, particularly duration of symptoms, we are unable to conclude synthetic cathinone-induced psychosis. Further research is warranted to elucidate the underlying mechanism linking synthetic cathinone consumption and psychosis. This review underscores the urgency of addressing the growing health risks posed by synthetic cathinone use. Additionally, it highlights the necessity of proper quantification of psychotic symptoms through scales and reporting of classification criteria to accurately diagnose SIPD.

Explanatory power by vagueness. Challenges to the strong prior hypothesis on hallucinations exemplified by the Charles-Bonnet-Syndrome

Predictive processing models are often ascribed a certain generality in conceptually unifying the relationships between perception, action, and cognition or the potential to posit a 'grand unified theory' of the mind. The limitations of this unification can be seen when these models are applied to specific cognitive phenomena or phenomenal consciousness. Our article discusses these shortcomings for predictive processing models of hallucinations by the example of the Charles-Bonnet-Syndrome. This case study shows that the current predictive processing account omits essential characteristics of stimulus-independent perception in general, which has critical phenomenological implications. We argue that the most popular predictive processing model of hallucinatory conditions - the strong prior hypothesis - fails to fully account for the characteristics of nonveridical perceptual experiences associated with Charles-Bonnet-Syndrome. To fill this explanatory gap, we propose that the strong prior hypothesis needs to include reality monitoring to apply to more than just veridical percepts.

Pseudo-hallucinations are for real in some patients with a bipolar disorder

OBJECTIVE

To provide exemplars of pseudo-hallucinations experienced by six individuals with bipolar disorder, suggest that they may be preferentially overrepresented in those with that condition and argue that their presence does not indicate that the individual is necessarily psychotic.

METHOD

Historical definitions of pseudo-hallucinations are overviewed and six profiles are presented considering manifestations in those with a bipolar disorder, their sequencing and response to medication.

RESULTS

The six patients initially judged such experiences as true hallucinations and, only over time, did they recognize their falsity. Clinical observation suggests that pseudo-hallucinations may be more common in those with a bipolar disorder and that they can precede, cooccur or follow disorder onset, can manifest during any phase of the condition and that they may or may not respond to medication prescribed for the bipolar disorder.

CONCLUSIONS

The exemplars of pseudo-hallucinations overviewed here indicate their richness of expression, their variable time course with illness stages and their variable response to medications prescribed for the bipolar condition.

Hallucinations and Hallucinogens: Psychopathology or Wisdom?

Hallucinations are currently associated almost exclusively with psychopathological states. While it is evident that hallucinations can indicate psychopathology or neurological disorders, we should remember that hallucinations also commonly occur in people without any signs of psychopathology. A similar case occurs in the case of hallucinogenic drugs, which have been long associated with psychopathology and insanity. However, during the last decades a huge body of research has shown that certain kinds of hallucinations, exerted by hallucinogenic drugs, may serve to improve mental health. We propose that, in light of historical, epidemiological, and scientific research, hallucinations can be better characterized as a common phenomenon associated sometimes with psychopathology but also with functional and even beneficial outcomes. In the last sections of the manuscript, we extend our argument, suggesting that hallucinations can offer a via regia to knowledge of the mind and the world. This radical shift in the cultural interpretation of hallucinations could have several implications for fields such as drug policy, civil law, and psychiatry, as well as for the stigma associated with mental disorders.

Stroke, Seizures, Hallucinations and Postoperative Delirium as Neurological Complications after Cardiac Surgery and Percutaneous Valve Replacement

(1) Background: Neurological complications such as acute ischemic stroke or postoperative delirium are frequent after cardiac surgery or percutaneous valve replacement. This study aimed to identify corresponding risk factors. (2) Methods: 297 patients with percutaneous valve replacement or cardiac surgery were postoperatively screened for neurological complications such as delirium, stroke, seizures and hallucinations twice daily for three days. Pre- and perioperative risk factors were evaluated in a multivariate model. (3) Results: Neurological complications occurred in 43.8% (n = 130) as composed of delirium (43.43%, n = 129), stroke (2.7%, n = 8), seizures (1.35%, n = 4) and real hallucinations (3.36%, n = 10). Multiple logistic regression revealed an association of neurological complications with lower Montreal Cognitive Assessment scores (Exp(B) 2.042; 95% CI, 1.183−3.525, p = 0.010), older age (Exp(B) 1.071; 95% CI, 1.036−1.107, p < 0.001), red blood cell transfusions until postoperative day 3 (Exp(B) 1.157; 95% CI, 1.030−1.300, p = 0.014), history of heart failure (Exp(B) 1.985; 95% CI, 1.130−3.487, p = 0.017) and increased CRP levels (Exp(B) 1.004; 95% CI, 1.000−1.008, p = 0.037). (4) Conclusions: Postoperative delirium remains a frequent complication after cardiac surgery, while stroke and seizures occur rarely. A preoperative risk profile including older age, history of heart failure and cognitive impairment was identified for a complicated postoperative course. However, the impact of an intense inflammatory response must not be neglected.

(Attenuated) hallucinations join basic symptoms in a transdiagnostic network cluster analysis

Hallucinations are considered characteristic symptoms of psychosis and part of the 'psychosis superspectrum' of the Hierarchical Taxonomy Of Psychopathology (HiTOP) initiative. To gain insight into their psychopathological relevance, we studied their dimensional placement within a single dense transdiagnostic network constituting of basic symptoms as well as of attenuated and frank psychotic, and related symptoms. Newman's modularity analysis was used to detect symptom clusters in an earlier generated network (Jimeno, N., et al., 2020. Main symptomatic treatment targets in suspected and early psychosis: New insights from network analysis. Schizophr. Bull. 46, 884-895. https://doi.org/10.1093/schbul/sbz140). The constituting 86 symptoms were assessed with the Schizophrenia Proneness Instrument, Adult version (SPI-A), the Structured Interview for Psychosis-Risk Syndromes (SIPS), and the Positive And Negative Syndrome Scale (PANSS) in three adult samples of an early detection service: clinical high-risk (n = 203), first-episode psychosis (n = 153), and major depression (n = 104). Three clusters were detected: "subjective disturbances", "positive symptoms and behaviors", and "negative and anxious-depressive symptoms". The predominately attenuated hallucinations of both SIPS and PANSS joined the basic symptoms in "subjective disturbances", whereas other positive symptoms entered "positive symptoms and behaviors". Our results underline the importance of insight in separating true psychotic hallucinations from other hallucinatory experiences that, albeit phenomenologically similar are still experienced with some insight, i.e., are present in an attenuated form. We conclude that, strictly, hallucinations held with any degree of insight should not be used to diagnose transition to or presence of frank psychoses and, relatedly, to justify antipsychotic medication.

The phenomenology of auditory verbal hallucinations in schizophrenia and the challenge from pseudohallucinations

In trying to make sense of the extensive phenomenological variation of first-personal reports on auditory verbal hallucinations, the concept of pseudohallucination is originally introduced to designate any hallucinatory-like phenomena not exhibiting some of the paradigmatic features of "genuine" hallucinations. After its introduction, Karl Jaspers locates the notion of pseudohallucinations into the auditory domain, appealing to a distinction between hallucinatory voices heard within the subjective inner space (pseudohallucination) and voices heard in the outer external space (real hallucinations) with differences in their sensory richness. Jaspers' characterization of the term has been the target of a number of phenomenological, conceptual and empirically-based criticisms. From this latter point of view, it has been claimed that the concept cannot capture distinct phenomena at the neurobiological level. Over the last years, the notion of pseudohallucination seems to be falling into disuse as no major diagnostic system seems to refer to it. In this paper, we propose that even if the concept of pseudohallucination is not helpful to differentiate distinct phenomena at the neurobiological level, the inner/outer distinction highlighted by Jaspers' characterization of the term still remains an open explanatory challenge for dominant theories about the neurocognitive origin of auditory verbal hallucinations. We call this, "the challenge from pseudohallucinations". After exploring this issue in detail, we propose some phenomenological, conceptual, and empirical paths for future research that might help to build up a more contextualized and dynamic view of auditory verbal hallucinatory phenomena.

Intracerebral Hemorrhage, Visual Hallucination and COVID-19: What Is the Connection? A Case-Related Review of the Literature on Peduncular Hallucinosis Following Intracerebral Hemorrhage

Previous publications have discussed the occurrence of intracerebral hemorrhages, hallucinations and psychosis in COVID-19 patients. In this article, we have reviewed the literature on the subject while depicting the case of a 63-year-old female patient who suffered from an intracerebral hemorrhage in the right basal ganglia and thalamus two weeks after a COVID-19 diagnosis and who developed a visual hallucinosis shortly after. We concluded that, while there may be a correlation between COVID-19 and hallucinations according to current literature, more research is yet needed to clarify. In our case, we rather interpreted the hallucinations in the context of a peduncular hallucinosis related to the intracerebral hemorrhage. We compared our patient’s lesion localization to other 15 reported cases of peduncular hallucinations following intracerebral hemorrhages reported on Pubmed. In summary, the lesions were localized in the pons in 52.9% of the cases, 17.7% were in the thalamus and/or the basal ganglia, 17.7% in the mesencephalon and respectively 5.8% in the temporal and occipital lobe. The distribution pattern we found is consistent with the previously proposed mechanism behind peduncular hallucinations.

Analgesic effects of intravenous ketamine after spinal anaesthesia for non-elective caesarean delivery: a randomised controlled trial

OBJECTIVES

This study aimed to determine if low dose intravenous ketamine is effective in reducing opioid use and pain after non-elective caesarean delivery.

DESIGN

Prospective, randomised, double-blind.

SETTING

Tertiary hospital, Bisheshwar Prasad Koirala Institute of Health Sciences, Dharan, Nepal PARTICIPANTS: 80 patients undergoing non-elective caesarean section with spinal anaesthesia.

INTERVENTIONS

Patients were allocated in 1:1 ratio to receive either intravenous ketamine 0.25 mg/kg or normal saline before the skin incision.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the total amount of morphine equivalents needed up to postoperative 24 hours. Secondary outcome measures were postoperative pain scores, time to the first perception of pain, maternal adverse effects (nausea, vomiting, hypotension, shivering, diplopia, nystagmus, hallucination) and neonatal Apgar score at 1 and 5 min, neonatal respiratory depression and neonatal intensive-care referral.

RESULTS

The median (range) cumulative morphine consumption during the first 24 hours of surgery was 0 (0-4.67) mg in ketamine group and 1 (0-6) mg in saline group (p=0.003). The median (range) time to the first perception of pain was 6 (1-12) hours and 2 (0.5-6) hours in ketamine and saline group, respectively (p<0.001). A significant reduction in postoperative pain scores was observed only at 2 hours and 6 hours in the ketamine group compared with placebo group (p<0.05). Maternal adverse effects and neonatal outcomes were comparable between the two groups.

CONCLUSIONS

Intravenous administration of low dose ketamine before surgical incision significantly reduced the opioid requirement in the first 24 hours in patients undergoing non-elective caesarean delivery.

TRIAL REGISTRATION NUMBER

NCT03450499.

Hearing Voices and Seeing Things: Symptoms of Anxiety Misconstrued as Evidence of Schizophrenia in an Adolescent

A patient's complaint of "hearing voices" or "seeing things" or of similar perceptual abnormalities leaves the clinician with 2 decisions: (1) Is the patient actually experiencing a hallucination, or does the complaint reflect a different mental experience, ranging from outright fabrication to the misinterpretation or mislabeling of vivid thoughts and emotions? (2) How should the experience reported by the patient, whether determined to be a hallucination or not, be understood in the context of the patient's entire history and mental state? We report the case of a 16-year-old whose cartoon-like hallucinations had led to the diagnosis of schizophrenia and had directed attention of the patient, her parents, and her clinicians away from critical issues of anxiety, depression, learning difficulties, and traumatic school experiences. This case illustrates how the diagnosis of schizophrenia can be driven by the prominence and vividness of psychotic-like symptoms reported by a patient, the expectation that patients' chief complaints must be directly and immediately addressed, insufficient attention to collateral information, and the distortions of a "checklist" approach to psychiatric diagnosis driven by the criteria in the Diagnostic and Statistical Manual of Mental Disorders, insurers, and the properties of electronic medical records. Given the consequences of either underdiagnosing or overdiagnosing schizophrenia, and the current lack of validated objective tests to assist with this diagnosis, clinicians are obligated to perform a thorough clinical assessment of such patients, including a probing exploration of the patient's mental state and a systematic collection of collateral information.

Functional Decoupling of Language and Self-Reference Networks in Patients with Persistent Auditory Verbal Hallucinations

BACKGROUND

Accumulating neuroimaging evidence suggests that abnormal intrinsic neural activity could underlie auditory verbal hallucinations (AVH) in patients with schizophrenia. However, little is known about the functional interplay between distinct intrinsic neural networks and their association with AVH.

METHODS

We investigated functional network connectivity (FNC) of distinct resting-state networks as well as the relationship between FNC strength and AVH symptom severity. Resting-state functional MRI data at 3 T were obtained for 14 healthy controls and 10 patients with schizophrenia presenting with persistent AVH. The data were analyzed using a spatial group independent component analysis, followed by constrained maximal lag correlations to determine FNC within and between groups.

RESULTS

Four components of interest, comprising language, attention, executive control networks, as well as the default-mode network (DMN), were selected for subsequent FNC analyses. Patients with persistent AVH showed lower FNC between the language network and the DMN (p < 0.05, corrected for false discovery rate). FNC strength, however, was not significantly related to symptom severity, as measured by the Psychotic Symptom Rating Scale.

CONCLUSION

These findings suggest that disrupted FNC between a speech-related system and a network subserving self-referential processing is associated with AVH. The data are consistent with a model of disrupted self-attribution of speech generation and perception.

Involuntary autobiographical memories and their relation to other forms of spontaneous thoughts

Involuntary autobiographical memories are memories of personal events that come to mind spontaneously-that is, with no conscious initiation of the retrieval process. Such spontaneously arising memories were long ignored in cognitive psychology, which generally has focused on controlled and strategic forms of remembering, studied in laboratory settings. Recent evidence shows that involuntary memories of past events are highly frequent in daily life, and that they represent a context-sensitive, and associative way of recollecting past events that involves little executive control. They operate by constraints that favour recent events and events with a distinct feature overlap to the current situation, which optimizes the probability of functional relevance to the ongoing situation. In addition to adults, they are documented in young children and great apes and may be an ontogenetic and evolutionary forerunner of strategic retrieval of past events. Findings suggest that intrusive involuntary memories observed clinically after traumatic events should be viewed as a dysfunctional subclass of otherwise functional involuntary autobiographical memories. Because of their highly constrained, situation-dependent and automatic nature, involuntary autobiographical memories form a distinct category of spontaneous thought that cannot be equated with mind wandering. This article is part of the theme issue 'Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation'.

Hallucinations and Illusions by Edmund Parish: the unlikely genesis and curious fate of a forgotten masterpiece

In 1894, the German scholar Edmund Parish published his classic work Über die Trugwahrnehmung, with an expanded English edition called Hallucinations and Illusions appearing in 1897. Both versions won critical acclaim from celebrities such as Joseph Jastrow and William James, although, curiously, few others seemed to have noticed the book. After two more publications, Parish inexplicably stopped publishing. During the century that followed, it seemed as if neither he nor his work had ever existed. Now that scholars have finally started to appreciate the book, the present paper seeks to answer the questions of how it came into being, why it disappeared for so long, and who its mysterious author was.

Hallucinations: diagnosis, neurobiology and clinical management

Hallucinations are important diagnostic symptoms in schizophrenia, but also occur in other medical and neuropsychiatric conditions. Not all patients with hallucinations are psychotic. There has been a surge of interest in the topic of hallucinations, as new research data have begun to reveal their neurobiology. Hallucinogenic molecules may also serve as new scaffolds for the development of new psychotropic drugs. We searched and reviewed recent literature, focusing on the refinement of clinical management, which was inspired by new data regarding the neurobiology of hallucination subtypes. We concluded that the successful management of hallucinations depends on accurate differential diagnosis to identify subtypes, which would then determine the most appropriate treatment.

Neuropsychiatric symptoms in brain diseases - historical foundations

Neuropsychiatric symptoms, which may appear alone or combined with cognitive and neurological manifestations, are frequent in many brain dysfunctions or lesions due to vascular, traumatic, neurodegenerative, or systemic conditions. Throughout history, many of the most prominent names have contributed to the clinical definition of the currently recognized mental symptoms and syndromes. The present paper aims at providing a comprehensive overview of the development, from ancient to modern times, of some widely known concepts and constructs about such neuropsychiatric disorders.

Voluntary control of auditory hallucinations: phenomenology to therapeutic implications

Auditory verbal hallucinations (AVH) have traditionally been thought to be outside the influence of conscious control. However, recent work with voice hearers makes clear that both treatment-seeking and non-treatment-seeking voice hearers may exert varying degrees of control over their voices. Evidence suggests that this ability may be a key factor in determining health status, but little systematic examination of control in AVH has been carried out. This review provides an overview of the research examining control over AVH in both treatment-seeking and non-treatment-seeking populations. We first examine the relationship between control over AVH and health status as well as the psychosocial factors that may influence control and functioning. We then link control to various cognitive constructs that appear to be important for voice hearing. Finally, we reconcile the possibility of control with the field’s current understanding of the proposed cognitive, computational, and neural underpinnings of hallucinations and perception more broadly. Established relationships between control, health status, and functioning suggest that the development of control over AVH could increase functioning and reduce distress. A more detailed understanding of the discrete types of control, their development, and their neural underpinnings is essential for translating this knowledge into new therapeutic approaches.

Hearing voices: From the Experience Qualification to the Possibility of Care

Abstract This article aimed to analyze hearing voices experiences in patients of a Psychosocial Care Center. In this regard, ten people were interviewed. The qualitative method was used, with content analysis. Four categories were chosen: “origin” of voices, phenomenology of voices, coping strategies, and family support. Hallucinatory experiences have emerged in contexts of violence and isolation. Topographic variables of the voices indicate possibilities of understanding the phenomenon. The movement is a basic condition to deal with the experiences. Family support is key to cope with difficulties. It is necessary to qualify the auditory hallucination as a meaningful experience, which must be respected in any intervention that intends care.

Nursing Process Addressing the Nursing Focus "Hallucination": A Scoping Review

Although hallucinations are prevalent in psychiatric disorders, such as psychosis or dementia, no studies were to be found in literature about the nursing process addressing the focus "Hallucination". This literature review, which is integrated with a scoping study framework, was performed to determine a clinical data model addressing the focus "Hallucination". PRISMA checklist for scoping reviews was followed. From the total of 328 papers found, 32 were selected. The findings of this review were summarized according to the nursing process addressing the focus "Hallucination". These findings led to determine a clinical data model addressing the focus "Hallucination", comprising the elements of the nursing process. This clinical data model may contribute toward improving nursing decision-making and nursing care quality in relation to a client suffering from hallucination, as well as contribute toward producing more reliable nursing-sensitive indicators.

Classic psychedelics: the special role of the visual system

Here, we briefly overview the various aspects of classic serotonergic hallucinogens reported by a number of studies. One of the key hypotheses of our paper is that the visual effects of psychedelics might play a key role in resetting fears. Namely, we especially focus on visual processes because they are among the most prominent features of hallucinogen-induced hallucinations. We hypothesize that our brain has an ancient visual-based (preverbal) intrinsic cognitive process that, during the transient inhibition of top-down convergent and abstract thinking (mediated by the prefrontal cortex) by psychedelics, can neutralize emotional fears of unconscious and conscious life experiences from the past. In these processes, the decreased functional integrity of the self-referencing processes of the default mode network, the modified multisensory integration (linked to bodily self-consciousness and self-awareness), and the modified amygdala activity may also play key roles. Moreover, the emotional reset (elimination of stress-related emotions) by psychedelics may induce psychological changes and overwrite the stress-related neuroepigenetic information of past unconscious and conscious emotional fears.

From Computation to the First-Person: Auditory-Verbal Hallucinations and Delusions of Thought Interference in Schizophrenia-Spectrum Psychoses

Schizophrenia-spectrum psychoses are highly complex and heterogeneous disorders that necessitate multiple lines of scientific inquiry and levels of explanation. In recent years, both computational and phenomenological approaches to the understanding of mental illness have received much interest, and significant progress has been made in both fields. However, there has been relatively little progress bridging investigations in these seemingly disparate fields. In this conceptual review and collaborative project from the 4th Meeting of the International Consortium on Hallucination Research, we aim to facilitate the beginning of such dialogue between fields and put forward the argument that computational psychiatry and phenomenology can in fact inform each other, rather than being viewed as isolated or even incompatible approaches. We begin with an overview of phenomenological observations on the interrelationships between auditory-verbal hallucinations (AVH) and delusional thoughts in general, before moving on to review several theoretical frameworks and empirical findings in the computational modeling of AVH. We then relate the computational models to the phenomenological accounts, with a special focus on AVH and delusions that involve the senses of agency and ownership of thought (delusions of thought interference). Finally, we offer some tentative directions for future research, emphasizing the importance of a mutual understanding between separate lines of inquiry.

Bleuler's Psychopathological Perspective on Schizophrenia Delusions: Towards New Tools in Psychotherapy Treatment

The authors begin by addressing the historical evolution of the delusion concept and its different approaches, focusing afterwards mainly on the work of Bleuler, who stressed the proximity between delusions and the emotional life of patients with schizophrenia. I Therefore, the present work intends to review the main aspects of the theory of delusion formation in schizophrenia according to Bleuler's psychopathological perspective. For that purpose, first the role of delusions in the psychopathology of schizophrenia is explored in a close relation with the Bleuler's fundamental symptoms (Alogia, Autism, Ambivalence, and Affect Blunting) nowadays known as negative symptoms. Then, persecutory, grandiosity and sexual delusions in schizophrenia are described according to the tension between logic and affects, as well as, internal conflict, schizoid features, and auto-erotism as key psychopathological pathways. Thus, with this subjective perspective, it is intended to highlight Bleuler's psychopathological contribution to the affective and meaningful causality of delusions in schizophrenia. The former might be useful in the integration with other psychopathological phenomena (hallucinations and negative symptoms) and new forms of research and therapeutic approaches in this disorder that are complementary with the contemporary tendencies in psychopathology.

Unique and Overlapping Symptoms in Schizophrenia Spectrum and Dissociative Disorders in Relation to Models of Psychopathology: A Systematic Review

Schizophrenia spectrum disorders (SSDs) and dissociative disorders (DDs) are described in the fifth edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM-5) and tenth edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) as 2 categorically distinct diagnostic categories. However, several studies indicate high levels of co-occurrence between these diagnostic groups, which might be explained by overlapping symptoms. The aim of this systematic review is to provide a comprehensive overview of the research concerning overlap and differences in symptoms between schizophrenia spectrum and DDs. For this purpose the PubMed, PsycINFO, and Web of Science databases were searched for relevant literature. The literature contained a large body of evidence showing the presence of symptoms of dissociation in SSDs. Although there are quantitative differences between diagnoses, overlapping symptoms are not limited to certain domains of dissociation, nor to nonpathological forms of dissociation. In addition, dissociation seems to be related to a history of trauma in SSDs, as is also seen in DDs. There is also evidence showing that positive and negative symptoms typically associated with schizophrenia may be present in DD. Implications of these results are discussed with regard to different models of psychopathology and clinical practice.

The Proximity between Hallucination and Delusion Dimensions: An Observational, Analytic, Cross-Sectional, Multicentre Study

In psychiatric classifications, hallucinations (mainly auditory hallucinations) are one of the fundamental criteria for establishing a schizophrenia diagnosis or any of the related psychotic disorder's diagnoses. The conceptual proximity between delusions and hallucinations was maintained until the end of the XIX century, with several supporters during the XX century. Their limits were not yet definitely defined in terms of Descriptive Psychopathology, and much less so in terms of biochemical and anatomical models. In this article we aimed to analyse the dimensions of both hallucinations and delusions in a sample of patients with schizophrenia and schizoaffective disorder. We also intend to find the determinants of the main dimensions of hallucinations. One hundred patients with schizophrenia (80) or schizoaffective disorder (20), 64% males, mean age 39.75, from the outpatient and inpatient units of the Psychiatry Department of Hospital de Santa Maria and the Centro Hospitalar Psiquiátrico de Lisboa were assessed by means of the Psychotic Symptom Rating Scales (PSYRATS) and a structured interview. In this study we designed an empirical based model by means of bivariate Spearman's rank correlation coefficient, and multivariate statistics (linear regression and multiple multivariate linear regression), where the main dimensions of hallucinations are determined by the central dimensions of delusions.