Studying hallucinations within the NIMH RDoC framework

Neuroscience-informed classification of prevention interventions in substance use disorders: An RDoC-based approach

Neuroscience has contributed to uncover the mechanisms underpinning substance use disorders (SUD). The next frontier is to leverage these mechanisms as active targets to create more effective interventions for SUD treatment and prevention. Recent large-scale cohort studies from early childhood are generating multiple levels of neuroscience-based information with the potential to inform the development and refinement of future preventive strategies. However, there are still no available well-recognized frameworks to guide the integration of these multi-level datasets into prevention interventions. The Research Domain Criteria (RDoC) provides a neuroscience-based multi-system framework that is well suited to facilitate translation of neurobiological mechanisms into behavioral domains amenable to preventative interventions. We propose a novel RDoC-based framework for prevention science and adapted the framework for the existing preventive interventions. From a systematic review of randomized controlled trials using a person-centered drug/alcohol preventive approach for adolescents, we identified 22 unique preventive interventions. By teasing apart these 22 interventions into the RDoC domains, we proposed distinct neurocognitive trajectories which have been recognized as precursors or risk factors for SUDs, to be targeted, engaged and modified for effective addiction prevention.

Altered brain responses to emotional auditory stimuli in AVH subjects: an fMRI study

Purpose: Auditory verbal hallucinations (AVH) are a frequently occurring phenomenon in which subjects hear verbal sounds in the absence of any external stimuli. The prevalence of auditory hallucinations in schizophrenia has been revealed in many studies. Healthy subjects may also experience auditory hallucinations without accompanying psychological or neurological disorders, and in rare cases they seek clinical assistance for this emotionally disturbing condition. The aim of this study was to investigate the neural basis of emotional disturbance in auditory hallucinating subjects who do not suffer from any psychological or neurological disorder. Materials and Methods: Fourteen subjects suffering from auditory hallucinations and 15 age- and sex-matched healthy controls were recruited in this study. All participants underwent fMRI in two experimental sessions. In the first experimental session, all participants from both groups listened to pleasant auditory stimuli. In the second session, both groups listened to unpleasant auditory stimuli. The auditory stimuli were obtained from the International Affective Digitized Sounds (IADS). Results: Compared with the healthy control group, AVH subjects exhibited significantly increased activation in limbic, auditory, and frontal regions. Conclusion: Current results suggest that AVH may induce functional reorganization in emotion-related brain regions.

Genetic bases of language control in bilinguals: Evidence from an EEG study

Previous studies have debated whether the ability for bilinguals to mentally control their languages is a consequence of their experiences switching between languages or whether it is a specific, yet highly-adaptive, cognitive ability. The current study investigates how variations in the language-related gene FOXP2 and executive function-related genes COMT, BDNF, and Kibra/WWC1 affect bilingual language control during two phases of speech production, namely the language schema phase (i.e., the selection of one language or another) and lexical response phase (i.e., utterance of the target). Chinese-English bilinguals (N = 119) participated in a picture-naming task involving cued language switches. Statistical analyses showed that both genes significantly influenced language control on neural coding and behavioral performance. Specifically, FOXP2 rs1456031 showed a wide-ranging effect on language control, including RTs, F(2, 113) = 4.00, FDR p = .036, and neural coding across three-time phases (N2a: F(2, 113) = 4.96, FDR p = .014; N2b: F(2, 113) = 4.30, FDR p = .028, LPC: F(2, 113) = 2.82, FDR p = .060), while the COMT rs4818 (ts >2.69, FDR ps < .05), BDNF rs6265 (Fs >5.31, FDR ps < .05), and Kibra/WWC1 rs17070145 (ts > -3.29, FDR ps < .05) polymorphisms influenced two-time phases (N2a and N2b). Time-resolved correlation analyses revealed that the relationship between neural coding and cognitive performance is modulated by genetic variations in all four genes. In all, these findings suggest that bilingual language control is shaped by an individual's experience switching between languages and their inherent genome.

Brain correlates of speech perception in schizophrenia patients with and without auditory hallucinations

The experience of auditory verbal hallucinations (AVH, "hearing voices") in schizophrenia has been found to be associated with reduced auditory cortex activation during perception of real auditory stimuli like tones and speech. We re-examined this finding using 46 patients with schizophrenia (23 with frequent AVH and 23 hallucination-free), who underwent fMRI scanning while they heard words, sentences and reversed speech. Twenty-five matched healthy controls were also examined. Perception of words, sentences and reversed speech all elicited activation of the bilateral superior temporal cortex, the inferior and lateral prefrontal cortex, the inferior parietal cortex and the supplementary motor area in the patients and the healthy controls. During the sentence and reversed speech conditions, the schizophrenia patients as a group showed reduced activation in the left primary auditory cortex (Heschl's gyrus) relative to the healthy controls. No differences were found between the patients with and without hallucinations in any condition. This study therefore fails to support previous findings that experience of AVH attenuates speech-perception-related brain activations in the auditory cortex. At the same time, it suggests that schizophrenia patients, regardless of presence of AVH, show reduced activation in the primary auditory cortex during speech perception, a finding which could reflect an early information processing deficit in the disorder.

Towards a machine-learning assisted diagnosis of psychiatric disorders and their operationalization in preclinical research: Evidence from studies on addiction-like behaviour in individual rats

Over the last few decades, there has been a progressive transition from a categorical to a dimensional approach to psychiatric disorders. Especially in the case of substance use disorders, interest in the individual vulnerability to transition from controlled to compulsive drug taking warrants the development of novel dimension-based objective stratification tools. Here we drew on a multidimensional preclinical model of addiction, namely the 3-criteria model, previously developed to identify the neurobehavioural basis of the individual's vulnerability to switch from controlled to compulsive drug taking, to test a machine-learning assisted classifier objectively to identify individual subjects as vulnerable/resistant to addiction. Datasets from our previous studies on addiction-like behaviour for cocaine or alcohol were fed into a variety of machine-learning algorithms to develop a classifier that identifies resilient and vulnerable rats with high precision and reproducibility irrespective of the cohort to which they belong. A classifier based on K-median or K-mean-clustering (for cocaine or alcohol, respectively) followed by artificial neural networks emerged as a highly reliable and accurate tool to predict if a single rat is vulnerable/resilient to addiction. Thus, each rat previously characterized as displaying 0-criterion (i.e., resilient) or 3-criteria (i.e., vulnerable) in individual cohorts was correctly labelled by this classifier. The present machine-learning-based classifier objectively labels single individuals as resilient or vulnerable to developing addiction-like behaviour in a multisymptomatic preclinical model of addiction-like behaviour in rats. This novel dimension-based classifier increases the heuristic value of these preclinical models while providing proof of principle to deploy similar tools for the future of diagnosis of psychiatric disorders.

Auditory Verbal Hallucinations in Schizophrenia, Part II: Phenomenological Qualities and Evolution

ABSTRACT

Hallucination is defined in the diagnostic systems as an experience resembling true perception without causal stimulus. In this second report from an in-depth phenomenological study of schizophrenia patients experiencing auditory verbal hallucinations (AVHs), we focused on the phenomenological qualities of AVHs. We found that a substantial proportion of patients could not clearly distinguish between thinking and hallucinating. The emotional tone of the voices increased in negativity. AVHs became more complex. Spatial localization was ambiguous and only 10% experienced only external hallucinations. There was an overlap with passivity phenomena in one third of the cases. The patients occasionally acted upon the content of AVHs. In the discussion section, we criticize the perceptual model of AVHs. We conclude that the definition of AVH in schizophrenia is misleading and exerts negative consequences on the clinical work and empirical research.

Maasai women hearing voices: Implications for global mental health

There is a sparse literature on women who hear voices globally, even though there are documented gendered dimensions of distress in the context of globalization and climate change and research indicates that trauma and psychosocial stress may be related to an increased prevalence of voice-hearing or auditory verbal hallucinations (AVHs). There is also a gap in the cultural phenomenology of voice-hearing in general, as well as idioms of distress for non-western peoples. This article presents results of a mixed methods study that: 1) estimated community prevalence of voice-hearing among Maasai women in northern Tanzania; 2) examined any demographic correlates and two specific hypothesized correlates (i.e., psychological stress and potentially traumatic events); and 3) engaged women in semi-structured interviews about their everyday lives and the phenomenological experience of voice-hearing. The prevalence of voice-hearing (39.4%) in this nonclinical sample (n = 71) was quite high compared to other studies in sub-Saharan Africa. Most women also reported high psychosocial stress and traumatic life events. They also talked about gendered conditions of social adversity in a context of rapid social, economic, and climate change. Women who reported hearing voices had a statistically significantly higher level of psychological distress, met criteria for severe psychological distress, and reported more potentially traumatic life events. In a logistic regression model, psychosocial stress predicted voice-hearing. The presence of distressing voices may offer a straightforward way to quickly identify people in the community experiencing the most extreme levels of psychosocial stress and traumatic events-a potentially simple but effective screening tool for health workers on the ground.

Neural Activation in the Ventromedial Prefrontal Cortex Precedes Conscious Experience of Being in or out of a Transient Hallucinatory State

BACKGROUND AND HYPOTHESES

Auditory verbal hallucinations (AVHs) is not only a common symptom in schizophrenia but also observed in individuals in the general population. Despite extensive research, AVHs are poorly understood, especially their underlying neuronal architecture. Neuroimaging methods have been used to identify brain areas and networks that are activated during hallucinations. A characteristic feature of AVHs is, however, that they fluctuate over time, with varying frequencies of starts and stops. An unanswered question is, therefore, what neuronal events co-occur with the initiation and inhibition of an AVH episode.

STUDY DESIGN

We investigated brain activation with fMRI in 66 individuals who experienced multiple AVH-episodes while in the scanner. We extracted time-series fMRI-data and monitored changes second-by-second from 10 s before to 15 s after participants indicated the start and stop of an episode, respectively, by pressing a hand-held response-button.

STUDY RESULTS

We found a region in the ventromedial prefrontal cortex (VMPFC) which showed a significant increase in activation initiated a few seconds before participants indicated the start of an episode, and a corresponding decrease in activation initiated a few seconds before the end of an episode.

CONCLUSIONS

The consistent increase and decrease in activation in this area in advance of the consciously experienced presence or absence of the "voice" imply that this region may act as a switch in turning episodes on and off. The activation is unlikely to be confounded by motor responses. The findings could have clinical implications for brain stimulation treatments, like transcranial magnetic stimulation.

(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.

Auditory verbal hallucinations as ictal phenomena in a patient with drug-resistant epilepsy

PURPOSE

The presence of verbal auditory hallucinations is often associated with psychotic disorders and rarely is considered as an ictal phenomena. The aim of this paper is to describe the anatomical structures involved in the genesis of this ictal symptom during epileptic seizures and direct cortical stimulation using stereo encephalography (SEEG).

METHOD

The case is of a 31-year-old right-handed female, bilateral speech representation, schizophrenia and with drug-resistant epilepsy and focal aware sensory seizures characterized by ictal verbal auditory hallucinations. She was implanted with depth electrodes, and she was monitored using SEEG recordings.

RESULTS

She had focal aware sensory seizures characterized by verbal auditory hallucinations, with the following features: hearing numerous voices (both male and/or female), talking at the same time (not able to distinguish how many). The voices were inside her head, consisted of negative content, and lasted up to two minutes. Some of her focal aware sensory seizures evolved to focal motor seizures and rarely progressed to bilateral tonic clonic seizures. Her neurological examination, her brain MRI and her interictal SPECT were unremarkable. Her PET scan identified mild hypo metabolism over the right temporal and right frontal lobes. Her neuropsychological evaluation showed language laterality undetermined but her functional MRI showed bilateral language representation. On her video-EEG, three seizures were captured with a right posterior temporal onset. A subsequent SEEG showed thirteen typical seizures originating from the posterior temporal neocortical region. The cortical stimulation of the right posterior temporo-parietal neocortical region and right amygdala triggered her typical phenomena, which was multiple voices, inside her head, speaking in the second person, negative content, unable to identify gender, in English, and no side lateralization.

CONCLUSION

Verbal auditory hallucinations should be analyzed carefully because they can be part of the seizure presentation. Our case supports the localization of these hallucinations in the right posterior neocortical temporal regions.

Exploring multimodal hallucinations and disturbances in the basic and bodily self: A cross-sectional study in a non-clinical sample

The bodily self is key to emotional embodiment, which is important for social functioning and emotion regulation. There is a paucity of research systematically assessing how basic and bodily self-disturbances relate to multimodal hallucinations. This study hypothesised that participants with greater hallucination-proneness would report greater degrees of basic and bodily self-disturbance and would demonstrate more ambiguous and less discrete mapping of emotional embodiment. Stage one screened non-clinical participants' degree of hallucination-proneness. Stage two participants completed seven further questionnaires. Hierarchical linear regression modelled the influence of hallucination-proneness and covariates on measures of basic and bodily self-disturbance and sensed presence. Stage two participants also completed a computerised body mapping task (EmBODY) which assessed emotional embodiment. Topographical maps were generated to compare patterns of embodiment between high and low hallucination-proneness groups. 55 respondents participated in stage two, with 18 participants from the high or low hallucination-proneness groups completing EmBODY. In the hierarchical regression analyses, the addition of a measure of hallucination proneness in the final step only increased predictive power where the dependent variable assessed sensed presence (p = 0.035 and p = 0.009, respectively). The EmBODY data revealed that participants with low hallucination-proneness consistently reported more bodily activation across 14 emotional states, whereas the high hallucination-proneness group reported more deactivation. In conclusion, hallucination-proneness was most strongly associated with sensed presence experiences. Patterns of embodiment appeared similar between the two groups, despite consistent differences in activation and deactivation. These findings are exploratory and need to be confirmed in a larger sample.

[Negative valence systems in the system of research domain criteria : Empirical results and new developments]

BACKGROUND

The research domain criteria (RDoC) domain of negative valence systems can be used to subsume long established and recently developed research approaches, which build upon theoretical knowledge and clinical practice of various psychiatric disorders.

OBJECTIVE

This article outlines how the five constructs within the RDoC domain of negative valence systems can contribute to integrating empirical studies into a coherent and differentiated biopsychosocial model.

MATERIAL AND METHODS

This is a qualitative review article that summarizes empirical results and discusses new developments on the basis of exemplary studies and selected reviews.

RESULTS AND DISCUSSION

The RDoC domain of negative valence systems differentiates in three constructs the time horizon, in which persons need to adequately react to (1) acute, (2) potential, and (3) sustained threats elicited by negative stimuli or situations. These three constructs can be outlined relatively well with specific experimental paradigms and neuronal circuits. Two further constructs focus on the negative consequences of (4) losses and (5) frustrative non-rewards. The former seems to be currently relatively diffusely defined whereas the latter is clearly circumscribed by its relation to specific forms of aggression. Behavioral, physiological, and neuronal reactions to acute and potential threats can be well compared between humans and animals and can be specified with the help of mathematical models. These models can contribute to a better understanding of how healthy and diseased persons process negative stimuli or situations.

The role of the gut microbiome in the development of schizophrenia

Schizophrenia is a heterogeneous neurodevelopmental disorder involving the convergence of a complex and dynamic bidirectional interaction of genetic expression and the accumulation of prenatal and postnatal environmental risk factors. The development of the neural circuitry underlying social, cognitive and emotional domains requires precise regulation from molecular signalling pathways, especially during critical periods or "windows", when the brain is particularly sensitive to the influence of environmental input signalling. Many of the brain regions involved, and the molecular substrates sub-serving these domains are responsive to life-long microbiota-gut-brain (MGB) axis signalling. This intricate microbial signalling system communicates with the brain via the vagus nerve, immune system, enteric nervous system, enteroendocrine signalling and production of microbial metabolites, such as short-chain fatty acids. Preclinical data has demonstrated that MGB axis signalling influences neurotransmission, neurogenesis, myelination, dendrite formation and blood brain barrier development, and modulates cognitive function and behaviour patterns, such as, social interaction, stress management and locomotor activity. Furthermore, preliminary clinical studies suggest altered gut microbiota profiles in schizophrenia. Unravelling MGB axis signalling in the context of an evolving dimensional framework in schizophrenia may provide a more complete understanding of the neurobiological architecture of this complex condition and offers the possibility of translational interventions.

Psychosis proneness, loneliness, and hallucinations in nonclinical individuals

Hallucinations occur along a continuum of normal functioning. Investigating the factors related to this experience in nonclinical individuals may offer important information for understanding the etiology of hallucinations in psychiatric populations. In this study we test the relationship between psychosis proneness, loneliness, and auditory hallucinations in a nonclinical sample using the White Christmas paradigm. Seventy-six undergraduate students participated in this study. We found that slightly more than half of our participants endorsed a hallucinatory experience during the White Christmas paradigm. However, we did not observe a relationship between the number of hallucinatory experiences and schizotypy, propensity to hallucinate, or loneliness. Moreover, there were no differences on these measures between individuals who reported hearing a hallucination during the White Christmas paradigm relative to those who did not. Thus, there may be other contextual factors not investigated in this study that might clarify the mechanism by which auditory hallucinations are experienced in a nonclinical population.

Hallucinations on demand: the utility of experimentally induced phenomena in hallucination research

Despite the desire to delve deeper into hallucinations of all types, methodological obstacles have frustrated development of more rigorous quantitative experimental techniques, thereby hampering research progress. Here, we discuss these obstacles and, with reference to visual phenomena, argue that experimentally induced phenomena (e.g. hallucinations induced by flickering light and classical conditioning) can bring hallucinations within reach of more objective behavioural and neural measurement. Expanding the scope of hallucination research raises questions about which phenomena qualify as hallucinations, and how to identify phenomena suitable for use as laboratory models of hallucination. Due to the ambiguity inherent in current hallucination definitions, we suggest that the utility of phenomena for use as laboratory hallucination models should be represented on a continuous spectrum, where suitability varies with the degree to which external sensory information constrains conscious experience. We suggest that existing strategies that group pathological hallucinations into meaningful subtypes based on hallucination characteristics (including phenomenology, disorder and neural activity) can guide extrapolation from hallucination models to other hallucinatory phenomena. Using a spectrum of phenomena to guide scientific hallucination research should help unite the historically separate fields of psychophysics, cognitive neuroscience and clinical research to better understand and treat hallucinations, and inform models of consciousness. This article is part of the theme issue 'Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation'.

Comparing Primary Voice-Hearers with and without Hallucinations in Other Sensory Modalities

There has been burgeoning interest in studying hallucinations in psychosis occurring across multiple sensory modalities. The current study aimed to characterize the auditory hallucination and delusion profiles in patients with auditory hallucinations only versus those with multisensory hallucinations. Participants with psychosis were partitioned into groups with voices only (AVH; n = 50) versus voices plus hallucinations in at least one other sensory modality (AVH+; n = 50), based on their responses on the Scale for the Assessment of Positive Symptoms (SAPS). Basic demographic and clinical information was collected, and the Questionnaire for Psychotic Experiences (QPE) was used to assess psychosis phenomenology. Relative to the AVH group, greater compliance to perceived commands, auditory illusions, and sensed presences was significantly elevated in the AVH+ group. The latter group also had greater levels of delusion-related distress and functional impairment and was more likely to endorse delusions of reference and misidentification. This preliminary study uncovered important phenomenological differences in those with multisensory hallucinations. Future hallucination research extending beyond the auditory modality is needed.

Precision Psychiatry: Biomarker-Guided Tailored Therapy for Effective Treatment and Prevention in Major Depression

Depression contributes greatly to global disability and is a leading cause of suicide. It has multiple etiologies and therefore response to treatment can vary significantly. By applying the concepts of personalized medicine, precision psychiatry attempts to optimize psychiatric patient care by better predicting which individuals will develop an illness, by giving a more accurate biologically based diagnosis, and by utilizing more effective treatments based on an individual's biological characteristics (biomarkers). In this chapter, we discuss the basic principles underlying the role of biomarkers in psychiatric pathology and then explore multiple biomarkers that are specific to depression. These include endophenotypes, gene variants/polymorphisms, epigenetic factors such as methylation, biochemical measures, circadian rhythm dysregulation, and neuroimaging findings. We also examine the role of early childhood trauma in the development of, and treatment response to, depression. In addition, we review how new developments in technology may play a greater role in the determination of new biomarkers for depression.

Mobile RDoC: Using Smartphones to Understand the Relationship Between Auditory Verbal Hallucinations and Need for Care

Objective

Auditory verbal hallucinations (AVH) are common in multiple clinical populations but also occur in individuals who are otherwise considered healthy. Adopting the National Institute of Mental Health's Research Domain Criteria (RDoC) framework, the aim of the current study was to integrate a variety of measures to evaluate whether AVH experience varies across clinical and nonclinical individuals.

Methods

A total of 384 people with AVH from 41 US states participated in the study; 295 participants (77%) who received inpatient, outpatient, or combination treatments for AVH and 89 participants (23%) who never received care. Participants used a multi-modal smartphone data collection system to report on their AVH experiences and co-occurring psychological states multiple times daily, over 30 days. In parallel, smartphone sensors recorded their physical activity, geolocation, and calling and texting behavior continuously.

Results

The clinical sample experienced AVH more frequently than the nonclinical group and rated their AVH as significantly louder and more powerful. They experienced more co-occurring negative affect and were more socially withdrawn, spending significantly more time at home and significantly less time near other people. Participants with a history of inpatient care also rated their AVH as infused with significantly more negative content. The groups did not differ in their physical activity or use of their smartphones for digital communication.

Conclusion

Smartphone-assisted remote data collection revealed real-time/real-place phenomenological, affective, and behavioral differences between clinical and nonclinical samples of people who experience AVH. The study provided strong support for the application of RDoC-informed approaches in psychosis research.

Using internal memory representations in associative learning to study hallucination-like phenomenon

Studies of Pavlovian conditioning have enriched our understanding of how relations among events can adaptively guide behavior through the formation and use of internal mental representations. In this review, we illustrate how internal representations flexibly integrate new updated information in reinforcer revaluation to influence relationships to impact actions and outcomes. We highlight representation-mediated learning to show the similarities in properties and functions between internally generated and directly activated representations, and how normal perception of internal representations could contribute to hallucinations. Converging evidence emerges from recent behavioral and neural activation studies using animal models of schizophrenia as well as clinical studies in patients to support increased tendencies in these populations to evoke internal representations from prior associative experience that approximate hallucination-like percepts. The heightened propensity is dependent on dopaminergic activation which is known to be sensitive to hippocampal overexcitability, a condition that has been observed in patients with psychosis. This presents a network that overlaps with cognitive neural circuits and offers a fresh approach for the development of therapeutic interventions targeting psychosis.

Hallucinating schizophrenia patients have longer left arcuate fasciculus fiber tracks: a DTI tractography study

The arcuate fasciculus (AF) has been implicated in the pathology behind schizophrenia and auditory verbal hallucinations (AVHs). White matter tracts forming the arcuate fasciculus can be quantified and visualized using diffusion tensor imaging (DTI) tractography. Although there have been a number of studies on this topic, the results have been conflicting. Studying the underlying white matter structure of the AF could shed light on the constrains for interaction between temporal and frontal language areas in AVHs. The participants were 66 patients with a schizophrenia diagnosis, where AVHs were defined from the Positive and Negative Syndrome Scale (PANSS), and compared with a healthy control group. DTI was performed on a 3T MR scanner, and tensor estimation was done using deterministic streamline tractography. Statistical analysis of the data showed significantly longer reconstructed tracks along the AF in patients with severe and frequent AVHs, as well as an overall significant asymmetry with longer tracks in the left compared to the right side. In addition, there were significant positive correlations between PANSS scores and track length, track volume, and number of track streamlines for the posterior AF segment on the left side. It is concluded that the present DTI results may have implications for interpretations of functional imaging results.

On the phenomenology of auditory verbal hallucinations in affective and non-affective psychosis

Phenomenological comparisons of auditory verbal hallucinations (AVHs) in affective versus non-affective psychosis have not been adequately documented. The current study aimed to: a) comprehensively describe AVH phenomenology by diagnosis and mood state, b) investigate significant predictors of voice-related distress and functional impairment, and c) conduct qualitative thematic analysis of participants' experiences. Participants were diagnosed with: a) bipolar disorder (n = 31), b) major depressive disorder (n = 34), c) schizophrenia (n = 50), or d) schizoaffective disorder (n = 26). Current voice-hearers were also subdivided into prevailing mood states: a) euthymic (n = 23), b) depressed (n = 51), or c) mania-mixed (n = 12). An in-depth, semi-structured interview was conducted, accompanied by mixed-methods analyses. Of the 34 AVH characteristics, significant group differences across diagnoses were identified only for frequency, number of voices, form of address, perceived location, level of conviction, beliefs regarding origin, and functional interference. Random forests modelling (RFM) showed experienced distress and functional interference were best predicted by discrete AVH variables. Qualitative thematic analysis revealed first-order themes: a) content, b) form, c) function, and d) non-voice. There were more similarities than differences in the phenomenology of AVHs across diagnoses, yet significant predictors of voice-related distress and functional impairment differed across affective and non-affective psychosis. This has important nosological and therapeutic applications.

Heterogeneity and Polygenicity in Psychiatric Disorders: A Genome-Wide Perspective

Genome-wide association studies (GWAS) have been performed for many psychiatric disorders and revealed a complex polygenic architecture linking mental and physical health phenotypes. Psychiatric diagnoses are often heterogeneous, and several layers of trait heterogeneity may contribute to detection of genetic risks per disorder or across multiple disorders. In this review, we discuss these heterogeneities and their consequences on the discovery of risk loci using large-scale genetic data. We primarily highlight the ways in which sex and diagnostic complexity contribute to risk locus discovery in schizophrenia, bipolar disorder, attention deficit hyperactivity disorder, autism spectrum disorder, posttraumatic stress disorder, major depressive disorder, obsessive-compulsive disorder, Tourette’s syndrome and chronic tic disorder, anxiety disorders, suicidality, feeding and eating disorders, and substance use disorders. Genetic data also have facilitated discovery of clinically relevant subphenotypes also described here. Collectively, GWAS of psychiatric disorders revealed that the understanding of heterogeneity, polygenicity, and pleiotropy is critical to translate genetic findings into treatment strategies.

Neuropsychiatric aspects of Parkinson disease psychopharmacology: Insights from circuit dynamics

Parkinson disease (PD) is a neurodegenerative disorder with a complex pathophysiology characterized by the progressive loss of dopaminergic neurons within the substantia nigra. Persons with PD experience several motoric and neuropsychiatric symptoms. Neuropsychiatric features of PD include depression, anxiety, psychosis, impulse control disorders, and apathy. In this chapter, we will utilize the National Institutes of Mental Health Research Domain Criteria (RDoC) to frame and integrate observations from two prevailing disease constructions: neurotransmitter anomalies and circuit physiology. When there is available evidence, we posit how unified translational observations may have clinical relevance and postulate importance outside of PD. Finally, we review the limited evidence available for pharmacologic management of these symptoms.

Searching for the Big Pictures

My goal in searching for the big pictures is to discover novel ways of organizing information in psychology that will have both theoretical and practical significance. The first section lists my reasons for writing each of five articles. The second section discusses an additional five articles that integrate advancements in artificial intelligence and cognitive psychology. The following two sections elaborate on my collaboration with ontologists to use formal ontologies to organize psychological knowledge, including the National Institute of Mental Health Research Domain Criteria, for formulating a biological basis for mental illness. I next discuss strategies for writing integrative articles. The following section describes the helpfulness of the integrations for making psychology relevant to a general audience. I conclude with recommendations for creating breadth in doctoral training.

Delusional themes in Body Dysmorphic Disorder (BDD): Comparisons with psychotic disorders and non-clinical Controls

The prevailing nosological classification of body dysmorphic disorder (BDD) encompasses an optional specifier "with absent insight/delusional beliefs" for patients who hold high conviction of the veracity of their disorder-specific beliefs. Yet limited research has examined the explicit nature of delusional beliefs in BDD. The current study therefore aimed to compare themes of delusional ideation in BDD relative to schizophrenia (SCZ) and healthy controls (HCs). Participants had a primary diagnosis of BDD (n = 44) or SCZ (n = 55), or were HCs (n = 55) with no personal or immediate family history of a diagnosable mental health disorder. Assessment of multidimensional delusional ideation was based on the Peters Delusional Inventory (PDI). Results showed that BDD and SCZ groups endorsed significantly more items, and had significantly elevated preoccupation and conviction than the HC group. Only the SCZ group exhibited significantly elevated distress relative to HC participants. In addition, BDD (akin to SCZ) participants were more likely to endorse somatic (appearance-related), control and thought alienation themes than the HC group. These findings suggest that delusional beliefs in BDD may not be strictly appearance-related, but rather span broader themes. This conveys therapeutic implications in terms of designing and administering targeted treatments aimed at delusional thinking in BDD.

Neuroimaging auditory verbal hallucinations in schizophrenia patient and healthy populations

BACKGROUND

Auditory verbal hallucinations (AVH) are a cardinal feature of schizophrenia, but they can also appear in otherwise healthy individuals. Imaging studies implicate language networks in the generation of AVH; however, it remains unclear if alterations reflect biologic substrates of AVH, irrespective of diagnostic status, age, or illness-related factors. We applied multimodal imaging to identify AVH-specific pathology, evidenced by overlapping gray or white matter deficits between schizophrenia patients and healthy voice-hearers.

METHODS

Diffusion-weighted and T1-weighted magnetic resonance images were acquired in 35 schizophrenia patients with AVH (SCZ-AVH), 32 healthy voice-hearers (H-AVH), and 40 age- and sex-matched controls without AVH. White matter fractional anisotropy (FA) and gray matter thickness (GMT) were computed for each region comprising ICBM-DTI and Desikan-Killiany atlases, respectively. Regions were tested for significant alterations affecting both SCZ-AVH and H-AVH groups, relative to controls.

RESULTS

Compared with controls, the SCZ-AVH showed widespread FA and GMT reductions; but no significant differences emerged between H-AVH and control groups. While no overlapping pathology appeared in the overall study groups, younger (<40 years) H-AVH and SCZ-AVH subjects displayed overlapping FA deficits across four regions (p < 0.05): the genu and splenium of the corpus callosum, as well as the anterior limbs of the internal capsule. Analyzing these regions with free-water imaging ascribed overlapping FA abnormalities to tissue-specific anisotropy changes.

CONCLUSIONS

We identified white matter pathology associated with the presence of AVH, independent of diagnostic status. However, commonalities were constrained to younger and more homogenous groups, after reducing pathologic variance associated with advancing age and chronicity effects.

The importance of loneliness in psychotic-like symptoms: Data from three studies

Poor social connection or loneliness is a prominent feature of schizotypy and may exacerbate psychosis risk. Previous studies have examined the inter-relationships between loneliness and psychosis risk, but critically, they have largely been conducted in non-clinical samples or exclusively used laboratory questionnaires with limited consideration of the heterogeneity within schizotypy (i.e., positive, negative, disorganized factors). The present study examined links between loneliness and psychotic-like symptoms across the dimensions of schizotypy through cross-sectional, laboratory-based questionnaires (Study 1; N = 160), ambulatory assessment (Study 2; N = 118) in undergraduates, and ambulatory assessment in inpatients in a substance abuse treatment program (Study 3; N = 48). Trait positive schizotypy consistently predicted cross-sectional and state psychotic-like symptoms. Loneliness, assessed via cross-sectional and ambulatory means, was largely linked with psychotic-like symptoms. Importantly, psychotic-like symptoms were dynamic: psychotic-like symptoms largely increased with loneliness in individuals with elevated positive and disorganized schizotypal traits, though there were some inconsistency related to disorganized schizotypy and state psychotic-like symptoms. Negative schizotypy and loneliness did not significantly interact to predict psychotic-like symptoms, suggesting specificity to positive schizotypy. Ambulatory approaches provide the opportunity for ecologically valid identification of risk states across psychopathology, thus informing early intervention.

Why context matters? Divisive normalization and canonical microcircuits in psychiatric disorders

Neural activity on cellular, regional, and behavioral levels shows context-dependence. Here we suggest the processing of input-output relationships in terms divisive normalization (DN), including (i) summing/averaging inputs and (ii) normalizing output against input stages, as a computational mechanism to underlie context-dependence. Input summation and output normalization are mediated by input-output relationships in canonical microcircuits (CM). DN/CM are altered in psychiatric disorders like schizophrenia or depression whose various symptoms can be characterized by abnormal context-dependence.

Are basic auditory processes involved in source-monitoring deficits in patients with schizophrenia?

Patients with schizophrenia (SZ) display deficits in both basic non-verbal auditory processing and source-monitoring of speech. To date, the contributions of basic auditory deficits to higher-order cognitive impairments, such as source-monitoring, and to clinical symptoms have yet to be elucidated. The aim of this study was to investigate the deficits and relationships between basic auditory functions, source-monitoring performances, and clinical symptom severity in SZ. Auditory processing of 4 psychoacoustic features (pitch, intensity, amplitude, length) and 2 types of source-monitoring (internal and reality monitoring) performances were assessed in 29 SZ and 29 healthy controls. Clinical symptoms were evaluated in patients with the Positive And Negative Syndrome Scale. Compared to the controls, SZ individuals in showed significant reductions in both global basic auditory processing (p < .0005, d = 1.16) and source-monitoring (p < .0005, d = 1.24) abilities. Both deficits correlated significantly in patients and across groups (all p < .05). Pitch processing skills were negatively correlated with positive symptom severity (r = -0.4, p < .05). A step-wise regression analysis showed that pitch discrimination was a significant predictor of source-monitoring performance. These results suggest that cognitive mechanisms associated with the discrimination of basic auditory features are most compromised in patients with source-monitoring disability. Basic auditory processing may index pathophysiological processes that are critical for optimal source-monitoring in schizophrenia and that are involved in positive symptoms.

Speaking-Induced Suppression of the Auditory Cortex in Humans and Its Relevance to Schizophrenia

Speaking-induced suppression (SIS) is the phenomenon that the sounds one generates by overt speech elicit a smaller neurophysiological response in the auditory cortex than comparable sounds that are externally generated. SIS is a specific example of the more general phenomenon of self-suppression. SIS has been well established in nonhuman animals and is believed to involve the action of corollary discharges. This review summarizes, first, the evidence for SIS in heathy human participants, where it has been most commonly assessed with electroencephalography and/or magnetoencephalography using an experimental paradigm known as "Talk-Listen"; and second, the growing number of Talk-Listen studies that have reported subnormal levels of SIS in patients with schizophrenia. This result is theoretically significant, as it provides a plausible explanation for some of the most distinctive and characteristic symptoms of schizophrenia, namely the first-rank symptoms. In particular, while the failure to suppress the neural consequences of self-generated movements (such as those associated with overt speech) provides a prima facie explanation for delusions of control, the failure to suppress the neural consequences of self-generated inner speech provides a plausible explanation for certain classes of auditory-verbal hallucinations, such as audible thoughts. While the empirical evidence for a relationship between SIS and the first-rank symptoms is currently limited, I predict that future studies with more sensitive experimental designs will confirm its existence. Establishing the existence of a causal, mechanistic relationship would represent a major step forward in our understanding of schizophrenia, which is a necessary precursor to the development of novel treatments.

Intentional inhibition but not source memory is related to hallucination-proneness and intrusive thoughts in a university sample

Proneness to unusual perceptual states - such as auditory or visual hallucinations - has been proposed to exist on a continuum in the general population, but whether there is a cognitive basis for such a continuum remains unclear. Intentional cognitive inhibition (the ability to wilfully control thoughts and memories) is one mechanism that has been linked to auditory hallucination susceptibility, but most evidence to date has been drawn from clinical samples only. Moreover, such a link has yet to be demonstrated over and above relations to other cognitive skills (source monitoring) and cognitive states (intrusive thoughts) that often correlate with both inhibition and hallucinations. The present study deployed two tests of intentional inhibition ability - the Inhibition of Currently Irrelevant Memories (ICIM) task and Directed Forgetting (DF) task - and one test of source monitoring (a source memory task) to examine how cognitive task performance relates to self-reported i) auditory hallucination-proneness and ii) susceptibility to intrusive thoughts in a non-clinical student sample (N = 76). Hierarchical regression analyses were used to assess the independent and combined contributions of task performance to proneness scores. ICIM performance but not DF or source memory scores were significantly related to both hallucination-proneness and intrusive thoughts. Further analysis suggested that intrusive thoughts may mediate the link between intentional inhibition skills and auditory hallucination-proneness, suggesting a potential pathway from inhibition to perception via intrusions in cognition. The implications for studying cognitive mechanisms of hallucination and their role in "continuum" views of psychosis-like experiences are discussed.

Adding Cognition to the Semanticscience Integrated Ontology

The goal of the NIMH RDoC initiative is to establish a biological basis for mental illness that includes linking cognition to molecular biology. A key challenge lies in how to represent such large, complex, and multi-scale knowledge in a manner that can support computational analysis, including query answering. Formal ontologies, such as the Semanticscience Integrated Ontology (SIO), offer a scaffold in which complex domain knowledge such as neurological and cognitive functions can be represented and linked to knowledge of molecular biology. In this article, we explore the use of SIO to represent concepts in molecular biology and in cognition. We extend SIO to traditional cognitive topics by illustrating axioms for both an information-processing and a neuroscience perspective on reading. We next discuss the NIMH RDoC taxonomy and include SIO axioms for the units-of-analysis and functions-of-behavior dimensions. An example demonstrates its use of deductive reasoning to establish causal relations across RDoC dimensions. From a broader perspective this article demonstrates how informatics can assist in integrating work in clinical psychology, cognitive psychology, cognitive neuroscience, computer science, molecular biology, and philosophy.

The Importance of Sensory Processing in Mental Health: A Proposed Addition to the Research Domain Criteria (RDoC) and Suggestions for RDoC 2.0

The time is ripe to integrate burgeoning evidence of the important role of sensory and motor functioning in mental health within the National Institute of Mental Health's [NIMH] Research Domain Criteria [RDoC] framework (National Institute of Mental Health, n.d.a), a multi-dimensional method of characterizing mental functioning in health and disease across all neurobiological levels of analysis ranging from genetic to behavioral. As the importance of motor processing in psychopathology has been recognized (Bernard and Mittal, 2015; Garvey and Cuthbert, 2017; National Institute of Mental Health, 2019), here we focus on sensory processing. First, we review the current design of the RDoC matrix, noting sensory features missing despite their prevalence in multiple mental illnesses. We identify two missing classes of sensory symptoms that we widely define as (1) sensory processing, including sensory sensitivity and active sensing, and (2) domains of perceptual signaling, including interoception and proprioception, which are currently absent or underdeveloped in the perception construct of the cognitive systems domain. Then, we describe the neurobiological basis of these psychological constructs and examine why these sensory features are important for understanding psychopathology. Where appropriate, we examine links between sensory processing and the domains currently included in the RDoC matrix. Throughout, we emphasize how the addition of these sensory features to the RDoC matrix is important for understanding a range of mental health disorders. We conclude with the suggestion that a separate sensation and perception domain can enhance the current RDoC framework, while discussing what we see as important principles and promising directions for the future development and use of the RDoC.

Hallucinations Beyond Voices: A Conceptual Review of the Phenomenology of Altered Perception in Psychosis

Recent psychiatric research and treatment initiatives have tended to move away from traditional diagnostic categories and have focused instead on transdiagnostic phenomena, such as hallucinations. However, this emphasis on isolated experiences may artificially limit the definition of such phenomena and ignore the rich, complex, and dynamic changes occurring simultaneously in other domains of experience. This article reviews the literature on a range of experiential features associated with psychosis, with a focus on their relevance for hallucinations. Phenomenological research on changes in cognition, perception, selfhood and reality, temporality, interpersonal experience, and embodiment are discussed, along with their implications for traditional conceptualizations of hallucinations. We then discuss several phenomenological and neurocognitive theories, as well as the potential impact of trauma on these phenomena. Hallucinations are suggested to be an equifinal outcome of multiple genetic, neurocognitive, subjective, and social processes; by grouping them together under a single, operationalizable definition, meaningful differences in etiology and phenomenology may be ignored. It is suggested that future research efforts strive to incorporate a broader range of experiential alterations, potentially expanding on traditional definitions of hallucinations. Relevance for clinical practice, including emphasizing phenomenologically responsive techniques and developing targeted new therapies, is discussed.

A comparison of visual hallucinations across disorders

Research into hallucinations typically regards them as single sensory or unimodal experiences leading to a comparative neglect of co-occurring multi-sensory hallucinations (MSH). People with psychosis who have visual hallucinations (VH) report high rates of hallucinations in other senses (auditory, olfactory, tactile). However, it is not known if this is similar to other groups who report VH. Consequently, this study explored MSH in four different patient groups who all had current VH. Archival data from standardised assessments of visual hallucinations in people with psychosis (n = 22), eye disease (ED) (n = 82), Lewy body Dementia (LBD) (n = 41), and Parkinson's disease (PD) (n = 41) determined the presence of MSH. People with psychosis and visual hallucinations reported significantly higher rates of MSH (auditory, 73%; tactile, 82%; olfactory/gustatory hallucinations, 27%) than the LBD group (auditory, 21%; tactile, 28%; olfactory/gustatory, 6%), ED (auditory, 1%; tactile, 11%; olfactory/gustatory, 0%) and PD patients (auditory, 3%; tactile, 8%; olfactory/gustatory, 3%). Regardless of diagnostic grouping, participants with MSH reported greater conviction that the VH were real, and reported greater distress. People with psychosis with VH report high rates of MSH unlike groups of older adults with VH. These between group differences in MSH prevalence have implications for clinical practice and theory.

No association between common genetic variation in FOXP2 and language impairment in schizophrenia

The FOXP2 gene is hypothesised to be involved in schizophrenia by affecting speech and language development. Associations between common single nucleotide polymorphisms (SNPs) in FOXP2 and language have been inconsistent. We tested five previously associated SNPs for association with language in the Western Australian Family Study of Schizophrenia (n = 709, including n = 333 with schizophrenia/spectrum disorder) and found no significant associations. When we included all common FOXP2 variants, one SNP (rs2189008) was nominally associated with language. This is the most comprehensive analysis to date and indicates that common variants in FOXP2 do not play a major role in speech and language development in a clinical family sample.

Associations between cortical thickness and auditory verbal hallucinations in patients with schizophrenia: A systematic review

Auditory verbal hallucinations are common symptoms in schizophrenia patients, and recent magnetic resonance imaging studies have suggested associations between cortical thickness and auditory verbal hallucinations. This article summarises the associations between cortical thickness reduction and auditory verbal hallucinations, conceptualising the findings based on the Research Domain Criteria framework. Six studies identified in a systematic literature search were included in the review. Cortical thickness reductions in schizophrenia patients with auditory verbal hallucinations were reported in the transverse temporal gyrus in four of the studies, in the superior temporal gyrus in three of them, and in the middle temporal gyrus in three of the studies. These regions are collectively associated with auditory perception in the cognitive system domain in the Research Domain Criteria. Findings in other brain areas were inconsistent, which may reflect uncharacterised differences in the phenomenology and subjective experience of auditory verbal hallucinations. Future studies are encouraged to apply the Research Domain Criteria to characterise other putative networks associated with the subjective experience of auditory verbal hallucinations. This approach may facilitate understanding of current inconsistencies between auditory verbal hallucinations and cortical thickness in other brain areas.

Extracellular Vesicles in Psychiatry Research in the Context of RDoC Criteria

The analysis of extracellular vesicles has been accelerated because of the technological advancements in omics methods in recent decades. Extracellular vesicles provide multifaceted information regarding the functional status of the cells. This information would be critical in case of central nervous system cells, which are confined in a relatively sealed biological compartment. This obstacle is more dramatic in psychiatric disorders since their diagnosis primarily depend on the symptoms and signs of the patients. In this paper, we reviewed this rapidly advancing field by discussing definition of extracellular vesicles, their biogenesis and potential use as clinical biomarkers. Then we focused on their potential use in psychiatric disorders in the context of diagnosis and treatment of these disorders. Finally, we tried to combine the RDoC (Research Domain Criteria) with the use of extracellular vesicles in psychiatry research and practice. This review may offer new insights in both basic and translational research focusing on psychiatric disorders.

A Review of the Effects of Transcranial Direct Current Stimulation for the Treatment of Hallucinations in Patients With Schizophrenia

Some 25% to 30% of patients with schizophrenia report auditory verbal hallucinations (AVHs) that fail to respond adequately to antipsychotic treatments. In such cases, transcranial direct current stimulation (tDCS) has been proposed as a therapeutic option. Here, we aim to provide an exhaustive review of the literature examining the clinical effects of tDCS on AVH in patients with schizophrenia. A systematic search in the PubMed and Web of Science databases yielded 14 results, 7 randomized controlled trials (RCTs) and 7 open-label studies. Among them, 4 RCTs and 7 open-label studies reported a significant reduction of AVH after repeated sessions of tDCS, whereas 3 RCTs did not show any advantage of active tDCS over sham tDCS. Altogether, current studies showed an overall decrease of approximately 26% of AVH after active tDCS and 11% after sham tDCS. One suitable approach to decreasing AVH was to deliver twice-daily sessions of tDCS over 5 consecutive days (10 sessions at 20 minutes each, 2 mA) with the anode over the left dorsolateral prefrontal cortex and the cathode over the left temporoparietal junction. Demographic and clinical parameters such as young age, nonsmoking status, and higher frequencies of AVH occurrence seemed to be predictors of clinical improvement. Further RCTs, with larger sample sizes, are needed to confirm the usefulness of tDCS for AVH.

Mitochondrial DNA copy number is associated with psychosis severity and anti-psychotic treatment

Mitochondrial pathology has been implicated in the pathogenesis of psychotic disorders. A few studies have proposed reduced leukocyte mitochondrial DNA (mtDNA) copy number in schizophrenia and bipolar disorder type I, compared to healthy controls. However, it is unknown if mtDNA copy number alteration is driven by psychosis, comorbidity or treatment. Whole blood mtDNA copy number was determined in 594 psychosis patients and corrected for platelet to leukocyte count ratio (mtDNAcn_res). The dependence of mtDNAcn_res on clinical profile, metabolic comorbidity and antipsychotic drug exposure was assessed. mtDNAcn_res was reduced with age (β = −0.210, p < 0.001), use of clozapine (β = −0.110,p = 0.012) and risperidone (β = −0.109,p = 0.014), dependent on prescribed dosage (p = 0.006 and p = 0.026, respectively), and the proportion of life on treatment (p = 0.006). Clozapine (p = 0.0005) and risperidone (p = 0.0126) had a reducing effect on the mtDNA copy number also in stem cell-derived human neurons in vitro at therapeutic plasma levels. For patients not on these drugs, psychosis severity had an effect (β = −0.129, p = 0.017), similar to age (β = −0.159, p = 0.003) and LDL (β = −0.119, p = 0.029) on whole blood mtDNAcn_res. Further research is required to determine if mtDNAcn_res reflects any psychosis-intrinsic mitochondrial changes.

Neuroimaging markers of antipsychotic treatment response in schizophrenia: An overview of magnetic resonance imaging studies

Antipsychotic drugs are the primary treatment for psychosis, yet individual response to their administration remains variable. At present, no biological predictors of response exist to guide clinicians as they select treatments for patients, and our understanding of the neurobiology underlying the heterogeneity of outcomes remains limited. Magnetic Resonance Imaging (MRI) has been applied by numerous studies to examine the response to antipsychotic treatment, though a large gap remains between their results and our clinical practice. To advance patient care with precision medicine approaches, prior work must be accounted for and built upon with future studies. This review provides an overview of studies that relate treatment outcome to various MRI-related measures, including structural, spectroscopic, diffusion tensor, and functional imaging. Knowledge derived from these studies will be discussed along with future directions for the field.

Are there clinical differences between inner, outer or dual spatial locations of auditory verbal hallucinations?

The aim of the present exploratory study was to examine the clinical differences of Auditory Verbal Hallucinations (AVHs) according to their spatial localization. Sixty-six outpatients were divided into three separate groups: inner, external and dual AVHs. The three groups were compared on sociodemographic variables (age, gender, education, marital status, living situation, employment, social disability), on clinical psychiatric characteristics (diagnosis, medication, comorbidities, illness onset, illness duration and hospitalizations) and on the measure yielded by the clinical assessments (Brief Psychiatric Rating Scale-Expanded, version 4.0; Maastricht Voices Interview for Adults; Belief About Voices Questionnaire Revised, the Clinical Global Impression, the Global Assessment Functioning Self-Esteem Rating Short Form, the World Health Organisation Quality of Life-Bref). Gender, living situation, social quality of life and some items regarding beliefs about AVHs raised significant difference, however most of the other comparisons failed to reach significance. Taken together, our findings suggest that all AVHs subtypes have equal clinical significance in patients presenting a chronic mental illness. However, the power of the study limits the generalization of the findings. Clinical implications of the findings are proposed.

Auditory hallucinations, not necessarily a hallmark of psychotic disorder

Auditory hallucinations (AH) are often considered a sign of a psychotic disorder. This is promoted by the DSM-5 category of Other Specified Schizophrenia Spectrum And Other Psychotic Disorder (OSSSOPD), the diagnostic criteria for which are fulfilled with the sole presence of persistent AH, in the absence of any other psychotic symptoms. And yet, persistent AH are not synonymous with having a psychotic disorder, and should therefore not be uncritically treated as such. Many people who seek treatment for persistent AH have no other psychotic symptoms, have preserved reality-testing capacities, and will never develop a schizophrenia spectrum disorder. Instead, hallucinations may be the result of many different causes, including borderline personality disorder, post-traumatic stress disorder (PTSD), hearing loss, sleep disorders or brain lesions, and they may even occur outside the context of any demonstrable pathology. In such cases, the usage of the DSM-5 diagnosis of OSSSOPD would be incorrect, and it may prompt unwarranted treatment with antipsychotic medication. We therefore argue that a DSM-5 diagnosis of Schizophrenia Spectrum Disorder (or any other type of psychotic disorder) characterized by AH should require at least one more symptom listed under the A-criterion (i.e. delusions, disorganized speech, disorganized or catatonic behavior or negative symptoms). Adhering to these more stringent criteria may help to distinguish between individuals with persistent AH which are part of a psychotic disorder, for whom antipsychotic medication may be helpful, and individuals with AH in the absence of such a disorder who may benefit from other approaches (e.g. different pharmacological interventions, improving coping style, trauma-related therapy).

Validating dimensions of psychosis symptomatology: Neural correlates and 20-year outcomes

Heterogeneity of psychosis presents significant challenges for classification. Between 2 and 12 symptom dimensions have been proposed, and consensus is lacking. The present study sought to identify uniquely informative models by comparing the validity of these alternatives. An epidemiologic cohort of 628 first-admission inpatients with psychosis was interviewed 6 times over 2 decades and completed an electrophysiological assessment of error processing at year 20. We first analyzed a comprehensive set of 49 symptoms rated by interviewers at baseline, progressively extracting from 1 to 12 factors. Next, we compared the ability of resulting factor solutions to (a) account for concurrent neural dysfunction and (b) predict 20-year role, social, residential, and global functioning, and life satisfaction. A four-factor model showed incremental validity with all outcomes, and more complex models did not improve explanatory power. The 4 dimensions-reality distortion, disorganization, inexpressivity, and apathy/asociality-were replicable in 5 follow-ups, internally consistent, stable across assessments, and showed strong discriminant validity. These results reaffirm the value of separating disorganization and reality distortion, are consistent with recent findings distinguishing inexpressivity and apathy/asociality, and suggest that these 4 dimensions are fundamental to understanding neural abnormalities and long-term outcomes in psychosis. (PsycINFO Database Record

Association Between Schizophrenia-Related Polygenic Liability and the Occurrence and Level of Mood-Incongruent Psychotic Symptoms in Bipolar Disorder

Importance

Bipolar disorder (BD) overlaps schizophrenia in its clinical presentation and genetic liability. Alternative approaches to patient stratification beyond current diagnostic categories are needed to understand the underlying disease processes and mechanisms.

Objective

To investigate the association between common-variant liability for schizophrenia, indexed by polygenic risk scores (PRSs), and psychotic presentations of BD.

Design, Setting, and Participants

This case-control study in the United Kingdom used multinomial logistic regression to estimate differential PRS associations across categories of cases and controls. Participants included in the final analyses were 4436 cases of BD from the Bipolar Disorder Research Network. These cases were compared with the genotypic data for 4976 cases of schizophrenia and 9012 controls from the Type 1 Diabetes Genetics Consortium study and the Generation Scotland study. Data were collected between January 1, 2000, and December 31, 2013. Data analysis was conducted from March 1, 2016, to February 28, 2017.

Exposures

Standardized PRSs, calculated using alleles with an association threshold of P < .05 in the second Psychiatric Genomics Consortium genome-wide association study of schizophrenia, were adjusted for the first 10 population principal components and genotyping platforms.

Main Outcomes and Measures

Multinomial logit models estimated PRS associations with BD stratified by Research Diagnostic Criteria subtypes of BD, by lifetime occurrence of psychosis, and by lifetime mood-incongruent psychotic features. Ordinal logistic regression examined PRS associations across levels of mood incongruence. Ratings were derived from the Schedules for Clinical Assessment in Neuropsychiatry interview and the Bipolar Affective Disorder Dimension Scale.

Results

Of the 4436 cases of BD, 2966 (67%) were female patients, and the mean (SD) age at interview was 46 [12] years. Across clinical phenotypes, there was an exposure-response gradient, with the strongest PRS association for schizophrenia (risk ratio [RR] = 1.94; 95% CI, 1.86-2.01), followed by schizoaffective BD (RR = 1.37; 95% CI, 1.22-1.54), bipolar I disorder subtype (RR = 1.30; 95% CI, 1.24-1.36), and bipolar II disorder subtype (RR = 1.04; 95% CI, 0.97-1.11). Within BD cases, there was an effect gradient, indexed by the nature of psychosis. Prominent mood-incongruent psychotic features had the strongest association (RR = 1.46; 95% CI, 1.36-1.57), followed by mood-congruent psychosis (RR = 1.24; 95% CI, 1.17-1.33) and BD with no history of psychosis (RR = 1.09; 95% CI, 1.04-1.15).

Conclusions and Relevance

For the first time to date, a study shows a polygenic-risk gradient across schizophrenia and BD, indexed by the occurrence and level of mood-incongruent psychotic symptoms.

Segregating polymorphisms of FOXP2 are associated with measures of inner speech, speech fluency and strength of handedness in a healthy population

We genotyped a healthy population for three haplotype-tagging FOXP2 SNPs, and tested for associations of these SNPs with strength of handedness and questionnaire-based metrics of inner speech characteristics (ISP) and speech fluency (FLU), as derived from the Schizotypal Personality Questionnaire-BR. Levels of mixed-handedness were positively correlated with ISP and FLU, supporting prior work on these two domains. Genotype for rs7799109, a SNP previously linked with lateralization of left frontal regions underlying language, was associated with degree of mixed handedness and with scores for ISP and FLU phenotypes. Genotype of rs1456031, which has previously been linked with auditory hallucinations, was also associated with ISP phenotypes. These results provide evidence that FOXP2 SNPs influence aspects of human inner speech and fluency that are related to lateralized phenotypes, and suggest that the evolution of human language, as mediated by the adaptive evolution of FOXP2, involved features of inner speech.

Plasma GDF15 level is elevated in psychosis and inversely correlated with severity

Accumulating evidence suggests that GDF15 is a biomarker for ageing and morbidity of many somatic disorders such as cancer and inflammatory disorders. Recently, elevated serum GDF15 level was proposed as a marker for mood disorder. However, psychosis severity was not investigated in relation to plasma GDF15 levels. In the present study we measured GDF15 levels in plasma of 120 psychosis patients compared to 120 age and gender matched healthy controls. Within the patient cohort GDF15 levels were evaluated for association with age, gender, lifestyle factors, C-reactive protein levels, psychosis severity and metabolic disorder. Psychosis patients had elevated GDF15 levels compared to controls (median_Psychosis = 744 ng/mL, median_controls = 516 ng/mL, p < 0.001). Within the psychosis cohort, GDF15 levels, when corrected for age, metabolic health and lifestyle factors, were negatively correlated with psychosis severity (β = −0.218, p = 0.012). While GDF15 levels were elevated in patients versus healthy controls, the negative correlation between psychosis severity and GDF15 suggests a loss of anti-inflammatory GDF15 mediated functionality in severe psychosis. Study replication in larger cohorts will be necessary to assess the potential of GDF15 as a prognostic biomarker in psychosis.