Combining novel trait and neurocognitive frameworks to parse heterogeneity in borderline personality disorder

OBJECTIVE

Borderline Personality Disorder (BPD) diagnosis comprises several constellations of trait, neurocognitive, and psychosocial alterations. Dimensional models of psychopathology provide new opportunities to parse heterogeneity and create a stronger interface between individual characterization and psychosocial outcomes. However, dimensional models have focused on either traits or neurocognitive features, lacking integration to capture the multifaceted nature of BPD.

METHOD

We assessed 100 participants with BPD using a combination of tools stemming from trait (Alternative Model for Personality Disorders) and neurocognitive models (Research Domain Criteria; RDoC) to examine if trait-derived subgroups display distinctive social-processing and psychosocial profiles. We used two complementary analytical approaches: person-centered (k-means clustering) and construct-based (multiple factor analysis).

RESULTS

Our person-centered approach identified four subgroups with separable internalizing, detached, externalizing, and low psychopathology trait profiles. These profiles revealed distinctive patterns of affiliation, emotion recognition and mentalization performance in RDoC tasks, and psychosocial measures of quality of life and social connectedness. RDoC-based measures showed close construct proximity with negative affectivity, disinhibition, and antagonism trait domains, relative to the detachment domain, which had close proximity with self-knowledge.

CONCLUSIONS

Altogether, findings support consilience between trait-based and neurobiological frameworks and suggest that trait models are useful to parse BPD heterogeneity leading to unique social functioning profiles.

Characterizing experiential elements of early-life stress to inform resilience: Buffering effects of controllability and predictability and the importance of their timing

Key theoretical frameworks have proposed that examining the impact of exposure to specific dimensions of stress at specific developmental periods is likely to yield important insight into processes of risk and resilience. Utilizing a sample of N = 549 young adults who provided a detailed retrospective history of their lifetime exposure to numerous dimensions of traumatic stress and ratings of their current trauma-related symptomatology via completion of an online survey, here we test whether an individual's perception of their lifetime stress as either controllable or predictable buffered the impact of exposure on trauma-related symptomatology assessed in adulthood. Further, we tested whether this moderation effect differed when evaluated in the context of early childhood, middle childhood, adolescence, and young adulthood stress. Consistent with hypotheses, results highlight both stressor controllability and stressor predictability as buffering the impact of traumatic stress exposure on trauma-related symptomatology and suggest that the potency of this buffering effect varies across unique developmental periods. Leveraging dimensional ratings of lifetime stress exposure to probe heterogeneity in outcomes following stress - and, critically, considering interactions between dimensions of exposure and the developmental period when stress occurred - is likely to yield increased understanding of risk and resilience following traumatic stress.

Similar overall expression, but different profiles, of autistic traits, sensory processing, and mental health between young adult males and females

Recent trends suggest that autism is more common in females than traditionally held. Additionally, some argue that females express autistic traits differently than males. Dimensional views of autism could shed light on these issues, especially with regards to understudied behavioral areas, such as sensory processing. We examined autistic traits, sensory processing, anxiety, and related behaviors in a large sample of neurotypical young adult males and females (n = 1,122; 556 female; ages 19-26). Participants completed an online survey containing questionnaires related to the above. Between groups statistical analyses, as well as within groups correlations and mediation analyses containing these constructs were then computed. We also carried out a cluster analysis to establish groups with behavioral similarities and estimate within-cluster male/female ratios. Results showed modest differences in the overall expression of autistic traits and sensory processing, if any, between males and females. Conversely, more detailed examination of survey subtests and mediation analyses revealed differing profiles between these groups. Cluster analysis uncovered a group comprised of both males (69.8%) and females (30.2%) who exhibited elevated degrees of autism-related behaviors, suggesting a higher proportion of females than would be predicted by traditional ratios. Taken together, these findings suggest that males and females may not differ as much as previously thought in their general levels of autistic traits or sensory processing, but may present with distinct profiles of such behaviors. These novel results add to our understanding of autistic traits in females and have the potential to positively influence diagnostic and support practices.

MAPping affective dimensions of behavior: Methodologic and pragmatic advancement of the Multidimensional Assessment Profiles scales

Rigorous validation of the full developmentally sensitive normal:abnormal spectrum, including evaluating the incremental value of age-specific behaviors, is necessary for nuanced characterization of dimensional features of psychopathology. To maximize the clinical utility of transdiagnostic approaches to risk identification, derivation of psychometrically sound, pragmatic versions with empirically derived cutoffs is also key. This special section has a central focus on rigorous, developmentally-based measurement of irritability as an exemplar of this theory- and pragmatically-based approach. Elevated irritability is a robust transdiagnostic predictor of the common psychopathologies of childhood. The Multidimensional Assessment Profiles Temper Loss (MAPS-TL) Scales are the only irritability tool specifically designed to capture the normal:abnormal dimensional spectrum. These have been extensively investigated in preschool age but lack rigorous modeling at older and younger ages. In this special issue, (with three independent-and one longitudinal-set of samples), we test and improve measurement of irritability as a transdiagnostic phenotype of psychopathology risk as it unfolds across development, expanding the MAPS-TL scale in three important ways: (1) extending irritability dimensional modeling and the developmental specification approach to older ages, (2) advancing science to practice translation by generating pragmatic irritability screening tools across ages, and (3) extending the dimensional, developmental specification approach to other dimensions of behavior, that is, internalizing. Collectively, the special issue operationalizes and advances application of a neurodevelopmental, dimensional and transdiagnostic approach to psychopathology.

A comparison of dimensional and discrete models for the representation of perceived and induced affect in response to short musical sounds

Introduction

In musical affect research, there is considerable discussion on the best method to represent affective response. This discussion mainly revolves around the dimensional (valence, tension arousal, energy arousal) and discrete (anger, fear, sadness, happiness, tenderness) models of affect. Here, we compared these models' ability to capture self-reported affect in response to short, affectively ambiguous sounds.

Methods

In two online experiments (n1 = 263, n2 = 152), participants rated perceived and induced affect in response to single notes (Exp 1) and chromatic scales (Exp 2), which varied across instrument family and pitch register. Additionally, participants completed questionnaires measuring pre-existing mood, trait empathy, Big-Five personality, musical sophistication, and musical preferences.

Results

Rater consistency and agreement were high across all affect scales. Correlation and principal component analyses showed that two dimensions or two affect categories captured most of the variation in affective response. Canonical correlation and regression analyses also showed that energy arousal varied in a manner that was not captured by discrete affect ratings. Furthermore, all sources of individual differences were moderately correlated with all affect scales, particularly pre-existing mood and dimensional affect.

Discussion

We conclude that when it comes to single notes and chromatic scales, the dimensions of valence and energy arousal best capture the perceived and induced affective response to affectively ambiguous sounds, although the role of individual differences should also be considered.

Categorical versus dimensional structure of autism spectrum disorder: A multi-method investigation

Background

A key question for any psychopathological diagnosis is whether the condition is continuous or discontinuous with typical variation. The primary objective of this study was to use a multi-method approach to examine the broad latent categorical versus dimensional structure of autism spectrum disorder (ASD).

Method

Data were aggregated across seven independent samples of participants with ASD, other neurodevelopmental disorders (NDD), and non-ASD/NDD controls (aggregate Ns = 512-16,755; ages 1.5-22). Scores from four distinct phenotype measures formed composite "indicators" of the latent ASD construct. The primary indicator set included eye gaze metrics from seven distinct social stimulus paradigms. Logistic regressions were used to combine gaze metrics within/across paradigms, and derived predicted probabilities served as indicator values. Secondary indicator sets were constructed from clinical observation and parent-report measures of ASD symptoms. Indicator sets were submitted to taxometric- and latent class analyses.

Results

Across all indicator sets and analytic methods, there was strong support for categorical structure corresponding closely to ASD diagnosis. Consistent with notions of substantial phenotypic heterogeneity, the ASD category had a wide range of symptom severity. Despite the examination of a large sample with a wide range of IQs in both genders, males and children with lower IQ were over-represented in the ASD category, similar to observations in diagnosed cases.

Conclusions

Our findings provide strong support for categorical structure corresponding closely to ASD diagnosis. The present results bolster the use of well-diagnosed and representative ASD groups within etiologic and clinical research, motivating the ongoing search for major drivers of the ASD phenotype. Despite the categorical structure of ASD, quantitative symptom measurements appear more useful for examining relationships with other factors.

A New Breakpoint to Classify 3D Voxels in MRI: A Space Transform Strategy with 3t2FTS-v2 and Its Application for ResNet50-Based Categorization of Brain Tumors

Three-dimensional (3D) image analyses are frequently applied to perform classification tasks. Herein, 3D-based machine learning systems are generally used/generated by examining two designs: a 3D-based deep learning model or a 3D-based task-specific framework. However, except for a new approach named 3t2FTS, a promising feature transform operating from 3D to two-dimensional (2D) space has not been efficiently investigated for classification applications in 3D magnetic resonance imaging (3D MRI). In other words, a state-of-the-art feature transform strategy is not available that achieves high accuracy and provides the adaptation of 2D-based deep learning models for 3D MRI-based classification. With this aim, this paper presents a new version of the 3t2FTS approach (3t2FTS-v2) to apply a transfer learning model for tumor categorization of 3D MRI data. For performance evaluation, the BraTS 2017/2018 dataset is handled that involves high-grade glioma (HGG) and low-grade glioma (LGG) samples in four different sequences/phases. 3t2FTS-v2 is proposed to effectively transform the features from 3D to 2D space by using two textural features: first-order statistics (FOS) and gray level run length matrix (GLRLM). In 3t2FTS-v2, normalization analyses are assessed to be different from 3t2FTS to accurately transform the space information apart from the usage of GLRLM features. The ResNet50 architecture is preferred to fulfill the HGG/LGG classification due to its remarkable performance in tumor grading. As a result, for the classification of 3D data, the proposed model achieves a 99.64% accuracy by guiding the literature about the importance of 3t2FTS-v2 that can be utilized not only for tumor grading but also for whole brain tissue-based disease classification.

Dimensional models of personality disorders: Challenges and opportunities

Categorical models of personality disorders have been beneficial throughout psychiatric history, providing a mechanism for organizing and communicating research and treatment. However, the view that individuals with personality disorders are qualitatively distinct from the general population is no longer tenable. This perspective has amassed steady criticism, ranging from inconsequential to irreconcilable. In response, stronger evidence has been accumulated in support of a dimensional perspective that unifies normal and pathological personality on underlying trait continua. Contemporary nosology has largely shifted toward this dimensional perspective, yet broader adoption within public lexicon and routine clinical practice appears slow. This review focuses on challenges and the related opportunities of moving toward dimensional models in personality disorder research and practice. First, we highlight the need for ongoing development of a broader array of measurement methods, ideally facilitating multimethod assessments that reduce biases associated with any single methodology. These efforts should also include measurement across both poles of each trait, intensive longitudinal studies, and more deeply considering social desirability. Second, wider communication and training in dimensional approaches is needed for individuals working in mental health. This will require clear demonstrations of incremental treatment efficacy and structured public health rebates. Third, we should embrace cultural and geographic diversity, and investigate how unifying humanity may reduce the stigma and shame currently generated by arbitrarily labeling an individual's personality as normal or abnormal. This review aims to organize ongoing research efforts toward broader and routine usage of dimensional perspectives within research and clinical spaces.

Cross-walking personality disorder types to ICD-11 trait domains: An overview of current findings

The ICD-11 has adopted a classification of Personality Disorders (PD) that abolishes the established categorical PD types in favor of global severity classification with specification of individual trait domains. To facilitate and guide this profound transition, an overview of current research on empirical associations between established PD types and ICD-11 trait domains seems warranted. We identified a total of 9 relevant studies from 2018 to 2022, which were based on both clinical and community samples from U.S., China, Brazil, Denmark, Spain, Korea, and Canada. The patterns of associations with ICD-11 trait domains were systematically synthesized and portrayed for each PD type. Findings overall showed expected and conceptually meaningful associations between categorical PD types and ICD-11 trait domains, with only few deviations. Based on these findings, we propose a cross-walk for translating categorical PD types into ICD-11 trait domains. More research is needed in order to further guide continuity and translation between ICD-10 and ICD-11 PD classification in mental healthcare, including facet-level ICD-11 trait information. Moreover, the nine reviewed studies only relied on self-reported ICD-11 trait domains, which should be expanded with clinician-rated trait domains in future research. Finally, future research should also take ICD-11's essential PD severity classification into account.

Examining the reliability and validity of the ICD-11 personality disorder severity diagnosis

OBJECTIVES

The International Classification of Diseases, 11th edition includes a new personality disorder diagnosis, in light of growing concerns of the categorical personality disorder diagnoses. The purpose of the current study was to examine the reliability and validity of the severity dimension of the new International Classification of Diseases, 11th edition diagnosis, through multi-method assessment.

METHOD

In a community mental health sample (n = 311), we examined the interrater reliability of the severity diagnosis and evaluated the diagnosis against self-report measures of dimensional personality pathology and psychopathology constructs and traditional categorical and informant-report measures.

RESULTS

Intraclass correlations indicated 'excellent' reliability of the diagnostic ratings. Large associations were observed between the International Classification of Diseases, 11th edition clinician diagnosis and overall impairment measures. Generally, the International Classification of Diseases, 11th edition clinician diagnosis exhibited largest associations with measures of internalising dysfunction, and more variable associations with interpersonal and externalising impairment. The International Classification of Diseases, 11th edition clinician diagnosis showed a large association with borderline personality disorder symptom scores and moderate associations with Paranoid, Schizoid and Avoidant personality disorder scores. Similar patterns emerged of the associations between the International Classification of Diseases, 11th edition personality disorder diagnosis with self-report and informant-report measures, although the associations were larger with self-report measures.

CONCLUSION

These findings provide promising initial evidence for the reliability and validity of the new International Classification of Diseases, 11th edition personality disorder diagnosis, indicating that the new conceptualisation of personality disorders may address issues within the categorical model.

Neurocognitive Artificial Neural Network Models Are Superior to Linear Models at Accounting for Dimensional Psychopathology

In recent years, there has been debate about the optimal conceptualisation of psychopathology. Structural models of psychopathology have been developed to counter issues, including comorbidity and poor diagnostic stability prevalent within the traditional nosological approach. Regardless of the conceptualisation of psychological dysfunction, deficits in neurocognitive abilities have been claimed to be an aetiological feature of psychopathology. Explorations of the association between neurocognition and psychopathology have typically taken a linear approach, overlooking the potential interactive dynamics of neurocognitive abilities. Previously, we proposed a multidimensional hypothesis, where within-person interactions between neurocognitive domains are fundamental to understanding the role of neurocognition within psychopathology. In this study, we used previously collected psychopathology data for 400 participants on psychopathological symptoms, substance use, and performance on eight neurocognitive tasks and compared the predictive accuracy of linear models to artificial neural network models. The artificial neural network models were significantly more accurate than the traditional linear models at predicting actual (a) lower-level and (b) high-level dimensional psychopathology. These results provide support for the multidimensional hypothesis: that the study of non-linear interactions and compensatory neurocognitive profiles are integral to understanding the functional associations between neurocognition and of psychopathology.

The Hierarchical Taxonomy of Psychopathology (HiTOP) in psychiatric practice and research

The Hierarchical Taxonomy of Psychopathology (HiTOP) has emerged out of the quantitative approach to psychiatric nosology. This approach identifies psychopathology constructs based on patterns of co-variation among signs and symptoms. The initial HiTOP model, which was published in 2017, is based on a large literature that spans decades of research. HiTOP is a living model that undergoes revision as new data become available. Here we discuss advantages and practical considerations of using this system in psychiatric practice and research. We especially highlight limitations of HiTOP and ongoing efforts to address them. We describe differences and similarities between HiTOP and existing diagnostic systems. Next, we review the types of evidence that informed development of HiTOP, including populations in which it has been studied and data on its validity. The paper also describes how HiTOP can facilitate research on genetic and environmental causes of psychopathology as well as the search for neurobiologic mechanisms and novel treatments. Furthermore, we consider implications for public health programs and prevention of mental disorders. We also review data on clinical utility and illustrate clinical application of HiTOP. Importantly, the model is based on measures and practices that are already used widely in clinical settings. HiTOP offers a way to organize and formalize these techniques. This model already can contribute to progress in psychiatry and complement traditional nosologies. Moreover, HiTOP seeks to facilitate research on linkages between phenotypes and biological processes, which may enable construction of a system that encompasses both biomarkers and precise clinical description.

Ab initioscreening of two-dimensional CuQxand AgQxchalcogenides

Two-dimensional (2D) chalcogenides have attracted great interest from the scientific community due to their intrinsic physical-chemical properties, which are suitable for several technological applications. However, most of the reported studies focused on particular compounds and composition, e.g., MoS₂, MoSe₂, WS₂, and WSe₂. Thus, there is an increased interest to extend our knowledge on 2D chalcogenides. Here, we report a density functional theory (DFT) screening of 2D coinage-metal chalcogenides (MQ_x), whereM= Cu, Ag,Q= S, Se, Te,x= 0.5, 1.0, 1.5, 2.0, with the aim to improve our atomistic understanding of the physical-chemical properties as a function of cation (M), anion (Q), and composition (x). Based on 258 DFT calculations, we selected a set of 22 stableMQ_xmonolayers based on phonons analyses, where we identified 9 semiconductors (7 AgQ_xand 2 CuQ_x), with band gaps from 0.07 eV up to 1.67 eV, while the remaining systems have a metallic character. Using all 258 systems, we found a logarithmic correlation between the average weighted bond lengths and effective coordination number of cations and anions. As expected, the monolayer cohesive energies increase with the radius of theQspecies (i.e., from S to Te). Furthermore, an increase in the anion size diminishes the work function for nearly allMQ_xmonolayers, which can be explained by the nature of the electronic states at the valence band maximum.

Examining the dimensionality of anxiety and depression: A latent profile approach to modeling transdiagnostic features

Depression and anxiety are highly prevalent psychological disorders; our understanding of these conditions remains limited. Efforts to explain anxiety and depression have been constrained in part by binary classification systems. Dimensional approaches to understanding psychopathology may be more effective. The present study used latent profile analysis (LPA) to assess whether unique subgroups exist within a tri-level model of anxiety and depression. Participants (N=627) completed self-report questionnaires from which tri-level model factors were derived. LPA was conducted on those factors. A 4-profile model offered optimal fit to the data at baseline. This model was replicated at a second time point. Models derived included profiles labelled 'Mixed Fears,' 'Anxious Arousal,' 'Low Mood/Anhedonia,' and 'Sub-Clinical.' Profiles were validated at Time 1 using diagnostic status and clinical severity ratings associated with mood and anxiety presentations. Profiles demonstrated flexibility in accommodating breadth in clinical presentations and common comorbidities. Latent variable models may offer more ecologically valid approaches to understanding psychopathology.

Dimensions of Formal Thought Disorder and Their Relation to Gray- and White Matter Brain Structure in Affective and Psychotic Disorders

Factorial dimensions and neurobiological underpinnings of formal thought disorders (FTD) have been extensively investigated in schizophrenia spectrum disorders (SSD). However, FTD are also highly prevalent in other disorders. Still, there is a lack of knowledge about transdiagnostic, structural brain correlates of FTD. In N = 1071 patients suffering from DSM-IV major depressive disorder, bipolar disorder, or SSD, we calculated a psychopathological factor model of FTD based on the SAPS and SANS scales. We tested the association of FTD dimensions with 3 T MRI measured gray matter volume (GMV) and white matter fractional anisotropy (FA) using regression and interaction models in SPM12. We performed post hoc confirmatory analyses in diagnostically equally distributed, age- and sex-matched sub-samples to test whether results were driven by diagnostic categories. Cross-validation (explorative and confirmatory) factor analyses revealed three psychopathological FTD factors: disorganization, emptiness, and incoherence. Disorganization was negatively correlated with a GMV cluster comprising parts of the middle occipital and angular gyri and positively with FA in the right posterior cingulum bundle and inferior longitudinal fascicle. Emptiness was negatively associated with left hippocampus and thalamus GMV. Incoherence was negatively associated with FA in bilateral anterior thalamic radiation, and positively with the hippocampal part of the right cingulum bundle. None of the gray or white matter associations interacted with diagnosis. Our results provide a refined mapping of cross-disorder FTD phenotype dimensions. For the first time, we demonstrated that their neuroanatomical signatures are associated with language-related gray and white matter structures independent of diagnosis.

Using major depression polygenic risk scores to explore the depressive symptom continuum

BACKGROUND

Major depression (MD) is often characterised as a categorical disorder; however, observational studies comparing sub-threshold and clinical depression suggest MD is continuous. Many of these studies do not explore the full continuum and are yet to consider genetics as a risk factor. This study sought to understand if polygenic risk for MD could provide insight into the continuous nature of depression.

METHODS

Factor analysis on symptom-level data from the UK Biobank (N = 148 957) was used to derive continuous depression phenotypes which were tested for association with polygenic risk scores (PRS) for a categorical definition of MD (N = 119 692).

RESULTS

Confirmatory factor analysis showed a five-factor hierarchical model, incorporating 15 of the original 18 items taken from the PHQ-9, GAD-7 and subjective well-being questionnaires, produced good fit to the observed covariance matrix (CFI = 0.992, TLI = 0.99, RMSEA = 0.038, SRMR = 0.031). MD PRS associated with each factor score (standardised β range: 0.057-0.064) and the association remained when the sample was stratified into case- and control-only subsets. The case-only subset had an increased association compared to controls for all factors, shown via a significant interaction between lifetime MD diagnosis and MD PRS (p value range: 2.23 × 10^-3-3.94 × 10^-7).

CONCLUSIONS

An association between MD PRS and a continuous phenotype of depressive symptoms in case- and control-only subsets provides support against a purely categorical phenotype; indicating further insights into MD can be obtained when this within-group variation is considered. The stronger association within cases suggests this variation may be of particular importance.

Latent classes of maladaptive personality traits exhibit differences in social processing

OBJECTIVE

Social processing (SP) deficits manifest across numerous mental disorders. However, this research has been plagued by heterogeneity and a piecemeal approach whereby skills are examined in isolation rather than as part of an integrated cognitive system. Here, we combined two dimensional frameworks of psychopathology to address these limitations.

METHOD

We utilized the Alternative Model for Personality Disorders (AMPD) to distill trait-related heterogeneity within a community sample (n = 200), and the Research Domain Criteria (RDoC) 'Systems for Social Processes' to comprehensively assess SP. We first applied latent class analyses (LCA) to derive AMPD-based groups and subsequently contrasted the performance of these groups on a SP test battery that we developed to align with the RDoC SP constructs.

RESULTS

Our LCA yielded four distinct subgroups. The recognizable trait profiles and psychopathological symptoms of these classes suggested they were clinically meaningful. The subgroups differed in their SP profiles: one displayed deficits regarding the self, a second displayed deficits in understanding others, a third displayed more severe deficits including affiliation problems, whilst the fourth showed normal performance.

CONCLUSIONS

Our results support the link between clusters of maladaptive personality traits and distinctive profiles of SP deficits, which may inform research on disorders involving SP dysfunctions.

The clinical utility of the ICD-11 classification of personality disorders and related traits: A preliminary scoping review

OBJECTIVES

A diagnostic system that fails to deliver clinically useful information will not be utilized and consequently will be unable to provide valuable data for health policy and clinical decision making. Therefore, it is imperative to obtain an accurate depiction of the clinical utility of the eleventh revision of the International Classification of Diseases (ICD-11) Personality Disorder (PD) model. The current mixed-methods systematic review aimed to determine the clinical utility of the ICD-11 PD classification system.

METHOD

An electronic screening of six databases was conducted and resulting studies were subjected to specific exclusion criteria, which elicited eight studies of interest. Study characteristics were tabulated and methodological quality was appraised.

RESULTS

Four studies offered strong support for the model's clinical utility, three offered some support accompanied by notable limitations and one study could only offer criticisms.

CONCLUSION

Future investigation of the ICD-11 PD classification system's (a) communicative value between clinicians and their patients, and between clinicians and their patient's families; (b) ease of use; and (c) feasibility in terms of practical application is required to achieve a complete understanding of its clinical utility and ultimately bring clarity to the current ambiguous findings.

Neurobiology and the Hierarchical Taxonomy of Psychopathology: progress toward ontogenetically informed and clinically useful nosology

The Hierarchical Taxonomy of Psychopathology (HiTOP) is an empirical structural model of psychological symptoms formulated to improve the reliability and validity of clinical assessment. Neurobiology can inform assessments of early risk and intervention strategies, and the HiTOP model has greater potential to interface with neurobiological measures than traditional categorical diagnoses given its enhanced reliability. However, one complication is that observed biological correlates of clinical symptoms can reflect various factors, ranging from dispositional risk to consequences of psychopathology. In this paper, we argue that the HiTOP model provides an optimized framework for conducting research on the biological correlates of psychopathology from an ontogenetic perspective that distinguishes among indicators of liability, current symptoms, and consequences of illness. Through this approach, neurobiological research can contribute more effectively to identifying individuals at high dispositional risk, indexing treatment-related gains, and monitoring the consequences of mental illness, consistent with the aims of the HiTOP framework.


Psychopathological Syndromes Across Affective and Psychotic Disorders Correlate With Gray Matter Volumes

INTRODUCTION

More than a century of research on the neurobiological underpinnings of major psychiatric disorders (major depressive disorder [MDD], bipolar disorder [BD], schizophrenia [SZ], and schizoaffective disorder [SZA]) has been unable to identify diagnostic markers. An alternative approach is to study dimensional psychopathological syndromes that cut across categorical diagnoses. The aim of the current study was to identify gray matter volume (GMV) correlates of transdiagnostic symptom dimensions.

METHODS

We tested the association of 5 psychopathological factors with GMV using multiple regression models in a sample of N = 1069 patients meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for MDD (n = 818), BD (n = 132), and SZ/SZA (n = 119). T1-weighted brain images were acquired with 3-Tesla magnetic resonance imaging and preprocessed with CAT12. Interactions analyses (diagnosis × psychopathological factor) were performed to test whether local GMV associations were driven by DSM-IV diagnosis. We further tested syndrome specific regions of interest (ROIs).

RESULTS

Whole brain analysis showed a significant negative association of the positive formal thought disorder factor with GMV in the right middle frontal gyrus, the paranoid-hallucinatory syndrome in the right fusiform, and the left middle frontal gyri. ROI analyses further showed additional negative associations, including the negative syndrome with bilateral frontal opercula, positive formal thought disorder with the left amygdala-hippocampus complex, and the paranoid-hallucinatory syndrome with the left angular gyrus. None of the GMV associations interacted with DSM-IV diagnosis.

CONCLUSIONS

We found associations between psychopathological syndromes and regional GMV independent of diagnosis. Our findings open a new avenue for neurobiological research across disorders, using syndrome-based approaches rather than categorical diagnoses.

Shared alterations in resting-state brain connectivity in adults with attention-deficit/hyperactivity disorder and their unaffected first-degree relatives

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a developmental condition that often persists into adulthood with extensive negative consequences on quality of life. Despite emerging evidence indicating the genetic basis of ADHD, investigations into the familial expression of latent neurocognitive traits remain limited.

METHODS

In a group of adult ADHD probands (n = 20), their unaffected first-degree relatives (n = 20) and typically developing control participants (n = 20), we assessed endophenotypic alterations in the default mode network (DMN) connectivity during resting-state functional magnetic resonance imaging in relation to cognitive performance and clinical symptoms. In an external validation step, we also examined the dimensional nature of this neurocognitive trait in a sample of unrelated healthy young adults (n = 100) from the Human Connectome Project (HCP).

RESULTS

The results illustrated reduced anti-correlations between the posterior cingulate cortex/precuneus and right middle frontal gyrus that was shared between adult ADHD probands and their first-degree relatives, but not with healthy controls. The observed connectivity alterations were linked to higher ADHD symptoms that was mediated by performance in a sustained attention task. Moreover, this brain-based neurocognitive trait dimensionally explained ADHD symptom variability in the HCP sample.

CONCLUSIONS

Alterations in the default mode connectivity may represent a dimensional endophenotype of ADHD, hence a significant aspect of the neuropathophysiology of this disorder. As such, brain network organisation can potentially be employed as an important neurocognitive trait to enhance statistical power of genetic studies in ADHD and as a surrogate efficacy endpoint in the development of novel pharmaceuticals.

Handover in Nursing: A Concept Analysis

BACKGROUND AND PURPOSE

The broad use of the term handover to describe any activity involving the transfer of professional responsibility from one person to another has led to an ambiguous understanding. Recently, handover has become a process central to the delivery of high-quality and safe patient care. The aim of this analysis was to clarify the concept of handover within the context of nursing practice.

METHODS

Rodgers's evolutionary approach was used as the analysis method along with some aspects of the dimensional analysis guided by Caron and Bowers, to understand the perspectives of senders and receivers.

RESULTS

The analysis revealed four attributes of handover: transfer of information, interaction for disambiguation, process, and strategy. Handover is defined as a process for transferring responsibility from sender to receiver through communication through the transfer of information, the interaction for disambiguation, and the context-sensitive strategy for accomplishing the continuity and safety of patient care. The salient dimension of handover was process, and the sub-dimensions were transfer of information, interaction for disambiguation, and strategy. From the sender's perspectives, it is the process of transferring information organized by the sender, and from the receiver's perspective, handover is the process establishing care plan through interactive strategy.

IMPLICATIONS FOR PRACTICE

The definition and identified attributes serve as a heuristic for designing strategies and further developing the construct of handover in nursing.

Categorical and Dimensional Diagnoses of Dyslexia: Are They Compatible?

Dyslexia is often assessed using categorical diagnoses, and subtypes of dyslexia are also recognized in a categorical fashion. Children may meet the criteria for dyslexia, and they may more specifically meet the criteria for a subtype of it, and thus get a diagnosis. This approach to diagnosis clashes with the actual distribution of reading performance in children (which is normal and continuous), and it has received criticism. This article offers a conceptual framework for conciliating these two positions. In short, the proposal is to use a set of multicomponent continuous assessments of reading, rather than thresholds. The proposal is explained using original data obtained from a sample of 30 children (age 7 to 11), tested in the United Kingdom. Using an assessment based on categorical-thresholds, only five children in our sample qualify for extra assistance, and only one may get a diagnosis of dyslexia, while with the mixed system proposed, a few additional children in the gray area would receive attention. This approach would not discard previous categorical approaches such as those distinguishing between surface and phonological dyslexia, but it would rather see these subtypes of dyslexia as the instance of a lower score on the continuum obtained on a single component of the multicomponent assessment.

A Concept Analysis of Neonatal Palliative Care in Nursing: Introducing a Dimensional Analysis

Despite the increasing need for neonatal palliative care, it is not adequately implemented in practice. This analysis aimed to clarify the dimension of the neonatal palliative care concept to increase understanding of the concept to give more insight into clinical practice. Using dimensional analysis methodology, 46 English language papers from 2001-2018 were analyzed. The coding of the literature for the perspective, context, conditions, process, and consequences of the concept was completed. Five dimensions informed the conceptualization of this concept and interrelationships among their themes/sub-themes were presented in the matrix named, "improving quality of life and death". Within the family-centered care perspective and under different conditions/contexts through the processes of neonate's comfort and providing holistic care, the consequences of this care were improving quality of life/a good death. Family-centered care was the fundamental dimension and essential to achieving the consequences. The other dimensions of context, conditions, and processes were also affected by the family's needs, preferences, culture, and expectations. This analysis reinforces that neonatal palliative care is a multidimensional concept. To provide the standard of neonatal palliative care an integrated plan to get together many stakeholders including community, parents, clinical staff, policymakers, insurance authorities, health care systems, and education system is required. All NICUs should have neonatal palliative care-trained nurses and protocols with a family-centered care approach to focus on the quality of life of neonates with life-threatening conditions from diagnosis of disease to death. Regular training and educational courses on neonatal palliative care and family-centered care principles can make nurses more sensitive to their advocacy role.

Transdiagnostic Prediction of Affective, Cognitive, and Social Function Through Brain Reward Anticipation in Schizophrenia, Bipolar Disorder, Major Depression, and Autism Spectrum Diagnoses

The relationship between transdiagnostic, dimensional, and categorical approaches to psychiatric nosology is under intense debate. To inform this discussion, we studied neural systems linked to reward anticipation across a range of disorders and behavioral dimensions. We assessed brain responses to reward expectancy in a large sample of 221 participants, including patients with schizophrenia (SZ; n = 27), bipolar disorder (BP; n = 28), major depressive disorder (MD; n = 31), autism spectrum disorder (ASD; n = 25), and healthy controls (n = 110). We also characterized all subjects with an extensive test battery from which a cognitive, affective, and social functioning factor was constructed. These factors were subsequently related to functional responses in the ventral striatum (vST) and neural networks linked to it. We found that blunted vST responses were present in SZ, BP, and ASD but not in MD. Activation within the vST predicted individual differences in affective, cognitive, and social functioning across diagnostic boundaries. Network alterations extended beyond the reward network to include regions implicated in executive control. We further confirmed the robustness of our results in various control analyses. Our findings suggest that altered brain responses during reward anticipation show transdiagnostic alterations that can be mapped onto dimensional measures of functioning. They also highlight the role of executive control of reward and salience signaling in the disorders we study and show the power of systems-level neuroscience to account for clinically relevant behaviors.

Dimensional Stability and Process Capability of an Industrial Component Injected with Recycled Polypropylene

The usage of recycled polymers for industrial purposes arises as one of the most promising methods of reducing environmental impact and costs associated with scrapping parts. This paper presents a systematic study of the dimensional stability of a raw and 100% recycled polypropylene subjected to realistic environmental conditions occurring along its working life. The component studied is an internal part of an induction hob assembly. Industrial samples manufactured with both materials, in the same mold, and in the same injection machine, are subjected to ejection conditions, storage conditions (50 °C), and extreme performance conditions (80 °C). Induced dimensional changes are registered and analyzed using a coordinate measuring machine, and a tactile sensing probe. To verify the process capability of the samples manufacturing, C_p and C_pk values are calculated to evaluate the suitability of the recycled material as an alternative. Results conclude that, although the use of recycled material implies slight differences in terms of dimensional stability due to the changes induced in the polymer structure, these differences are not significant enough to affect the injection process capability. Therefore, recycling arises as one effective method to reduce both overruns associated with the consumption of raw polypropylene material and its environmental impact.

The Translational Potential of Neuroimaging Genomic Analyses To Diagnosis And Treatment In The Mental Disorders

Imaging genomics focuses on characterizing genomic influence on the variation of neurobiological traits, holding promise for illuminating the pathogenesis, reforming the diagnostic system, and precision medicine of mental disorders. This paper aims to provide an overall picture of the current status of neuroimaging-genomic analyses in mental disorders, and how we can increase their translational potential into clinical practice. The review is organized around three perspectives. (a) Towards reliability, generalizability and interpretability, where we summarize the multivariate models and discuss the considerations and trade-offs of using these methods and how reliable findings may be reached, to serve as ground for further delineation. (b) Towards improved diagnosis, where we outline the advantages and challenges of constructing a dimensional transdiagnostic model and how imaging genomic analyses map into this framework to aid in deconstructing heterogeneity and achieving an optimal stratification of patients that better inform treatment planning. (c) Towards improved treatment. Here we highlight recent efforts and progress in elucidating the functional annotations that bridge between genomic risk and neurobiological abnormalities, in detecting genomic predisposition and prodromal neurodevelopmental changes, as well as in identifying imaging genomic biomarkers for predicting treatment response. Providing an overview of the challenges and promises, this review hopefully motivates imaging genomic studies with multivariate, dimensional and transdiagnostic designs for generalizable and interpretable findings that facilitate development of personalized treatment.

Use of Three-Dimensional Printing Techniques in the Management of a Patient Suffering From Traumatic Loss of the Talus

Traumatic loss of the whole talus is extremely rare, and its possible treatment options are limited. Our experience of treatment of a 30-year-old male suffering from traumatic loss of the whole talus with the insertion of an anatomical antibiotic-loaded talus cement spacer using 3-dimensional printing techniques as an interim measure was reviewed and reported. A young motorcyclist was brought to the emergency department after a road traffic accident. He sustained multiple injuries including traumatic loss of his left talus. Despite repeated surgeries of debridement and insertion of external fixator to his injured ankle, the patient had residual problem of ankle instability, ankle infection, and absence of his involved talus. With the help of computerized 3-dimensional printing techniques, an anatomical talus cement spacer was produced in the operating room and inserted into the patient's ankle 7 weeks after the initial trauma. The external fixator was kept for another 3 weeks before removal. At 14 months after the insertion of cement spacer, the patient could walk independently without any pain for 15 minutes with the help of a crutch occasionally. However, the range of motion of his left ankle was limited to 15° in the flexion-extension arc and minimal subtalar motion. The infection of the left ankle was under control.

Preliminary validation of the Yale Food Addiction Scale for Children 2.0: A dimensional approach to scoring

OBJECTIVE

Assessment approaches for food addiction in younger samples have not been updated to reflect recently revised diagnostic approaches for addictive disorders. The aim of the current study is to develop a new dimensional approach to assess food addiction in adolescents that is psychometrically sound, developmentally appropriate, and reflective of the updated diagnostic criteria.

METHODS

The dimensional Yale Food Addiction Scale for Children 2.0 (dYFAS-C 2.0) and related measures were administered to 127 adolescents from the community in the United States. Endorsement rates for each question were reviewed, and the psychometric properties were evaluated.

RESULTS

Problem-focused symptoms had low endorsement rates and were excluded from the final version of the scale. The dYFAS-C 2.0 demonstrated partial evidence for a one-factor structure, had good internal consistency reliability, and was positively associated with emotional eating, external eating, and body mass index (BMI). The dYFAS-C 2.0 also accounted for unique variance in BMI. Unexpectedly, the dYFAS-C 2.0 was positively associated with restrained eating.

CONCLUSIONS

The dYFAS-C 2.0 appears to have adequate psychometric properties for assessing food addiction in community samples of adolescents. Future research should evaluate the measure in clinical samples and investigate the association between food addiction and restrained eating over the lifespan.

Do Individual Differences Influence Moment-by-Moment Reports of Emotion Perceived in Music and Speech Prosody?

Comparison of emotion perception in music and prosody has the potential to contribute to an understanding of their speculated shared evolutionary origin. Previous research suggests shared sensitivity to and processing of music and speech, but less is known about how emotion perception in the auditory domain might be influenced by individual differences. Personality, emotional intelligence, gender, musical training and age exert some influence on discrete, summative judgments of perceived emotion in music and speech stimuli. However, music and speech are temporal phenomena, and little is known about whether individual differences influence moment-by-moment perception of emotion in these domains. A behavioral study collected two main types of data: continuous ratings of perceived emotion while listening to extracts of music and speech, using a computer interface which modeled emotion on two dimensions (arousal and valence), and demographic information including measures of personality (TIPI) and emotional intelligence (TEIQue-SF). Functional analysis of variance on the time series data revealed a small number of statistically significant differences associated with Emotional Stability, Agreeableness, musical training and age. The results indicate that individual differences exert limited influence on continuous judgments of dynamic, naturalistic expressions. We suggest that this reflects a reliance on acoustic cues to emotion in moment-by-moment judgments of perceived emotions and is further evidence of the shared sensitivity to and processing of music and speech.

Evaluation of cavity size, kind, and filling technique of composite shrinkage by finite element

Background:

Cavity preparation reduces the rigidity of tooth and its resistance to deformation. The purpose of this study was to evaluate the dimensional changes of the repaired teeth using two types of light cure composite and two methods of incremental and bulk filling by the use of finite element method.

Materials and Methods:

In this computerized in vitro experimental study, an intact maxillary premolar was scanned using cone beam computed tomography instrument (SCANORA, Switzerland), then each section of tooth image was transmitted to Ansys software using AUTOCAD. Then, eight sizes of cavity preparations and two methods of restoration (bulk and incremental) using two different types of composite resin materials (Heliomolar, Brilliant) were proposed on software and analysis was completed with Ansys software.

Results:

Dimensional change increased by widening and deepening of the cavities. It was also increased using Brilliant composite resin and incremental filling technique.

Conclusion:

Increase in depth and type of filling technique has the greatest role of dimensional change after curing, but the type of composite resin does not have a significant role.

Clarifying the Conceptualization, Dimensionality, and Structure of Emotion: Response to Barrett and Colleagues

We present a mathematically based framework distinguishing the dimensionality, structure, and conceptualization of emotion-related responses. Our recent findings indicate that reported emotional experience is high-dimensional, involves gradients between categories traditionally thought of as discrete (e.g., 'fear', 'disgust'), and cannot be reduced to widely used domain-general scales (valence, arousal, etc.). In light of our conceptual framework and findings, we address potential methodological and conceptual confusions in Barrett and colleagues' commentary on our work.

Non-medical Cannabis Self-Exposure as a Dimensional Predictor of Opioid Dependence Diagnosis: A Propensity Score Matched Analysis

Background: The impact of increasing non-medical cannabis use on vulnerability to develop opioid use disorders has received considerable attention, with contrasting findings. A dimensional analysis of self-exposure to cannabis and other drugs, in individuals with and without opioid dependence (OD) diagnoses, may clarify this issue. Objective: To examine the age of onset of maximal self-exposure to cannabis, alcohol, cocaine, and heroin, in volunteers diagnosed with OD, using a rapidly administered instrument (the KMSK scales). To then determine whether maximal self-exposure to cannabis, alcohol, and cocaine is a dimensional predictor of odds of OD diagnoses. Methods: This outpatient observational study examined maximal self-exposure to these drugs, in volunteers diagnosed with DSM-IV OD or other drug diagnoses, and normal volunteers. In order to focus more directly on opioid dependence diagnosis as the outcome, volunteers who had cocaine dependence diagnoses were excluded. Male and female adults of diverse ethnicity were consecutively ascertained from the community, and from local drug treatment programs, in 2002-2013 (n = 574, of whom n = 94 had OD diagnoses). The age of onset of maximal self-exposure of these drugs was examined. After propensity score matching for age at ascertainment, gender, and ethnicity, a multiple logistic regression examined how increasing self-exposure to non-medical cannabis, alcohol and cocaine affected odds of OD diagnoses. Results: Volunteers with OD diagnoses had the onset of heaviest use of cannabis in the approximate transition between adolescence and adulthood (mean age = 18.9 years), and onset of heaviest use of alcohol soon thereafter (mean age = 20.1 years). Onset of heaviest use of heroin and cocaine was detected later in the lifespan (mean ages = 24.7 and 25.3 years, respectively). After propensity score matching for demographic variables, we found that the maximal self-exposure to cannabis and cocaine, but not to alcohol, was greater in volunteers with OD diagnoses, than in those without this diagnosis. Also, a multiple logistic regression detected that increasing self-exposure to cannabis and cocaine, but not alcohol, was a positive predictor of OD diagnosis. Conclusions/Importance: Increasing self-exposure to non-medical cannabis, as measured with a rapid dimensional instrument, was a predictor of greater odds of opioid dependence diagnosis, in propensity score-matched samples.

The latent structure of social anxiety disorder and the performance only specifier: a taxometric analysis

Social anxiety disorder (SAD) is often treated as a discrete diagnostic entity that represents a naturally occurring class, though empirical evidence largely supports a dimensional conceptualization of social fears. Further, the inclusion of a "performance only" specifier in the DSM-5 implies that individuals who experience intense social anxiety exclusively in performance situations are distinct from those with broader social fears. The purpose of the present research was to examine the latent structure of SAD and the DSM-5 "performance only" specifier in a large nonclinical sample (n = 2019). Three taxometric procedures (MAXCOV, MAMBAC, and L-Mode) were applied to indicators derived from two commonly used measures of social anxiety. Results yielded convergent evidence indicating that social anxiety exhibits a dimensional latent structure. Further, social performance anxiety demonstrates continuous relationships with milder social fears, suggesting that the "performance only" specifier may not represent a discrete entity. The implications of these findings for the assessment, diagnosis, classification, and treatment of social anxiety are discussed.

Application of structural equation mixture modeling to characterize the latent structure of eating pathology

OBJECTIVE

Several theoretical models describe the structure of eating disorders (EDs), and a burgeoning empirical literature has sought to identify whether eating pathology is conceptualized best as categorical (presence or absence of disorder), dimensional (continuous), or a hybrid of categories and dimensions.

METHODS

This study used structural equation mixture modeling (SEMM) to identify the latent structure of EDs. Items from the Eating Pathology Symptoms Inventory (EPSI) were administered to individuals with EDs (N = 344). Select EPSI scales and body mass index were indicators in subsequent SEMM analyses. The Inventory of Depression and Anxiety Symptoms (IDAS), ED diagnoses, and select demographic variables were used as validators using chi-square or MANOVA.

RESULTS

Categorical models fit the data better than latent dimensional or hybrid models. Latent profile 1 (LP1) was non-fat-phobic restricting anorexia nervosa; LP2, an obese, binge-eating class; LP3, non-purging bulimia nervosa; LP4, fat-phobic restricting anorexia nervosa; and LP5, multiple purging bulimia nervosa. External validation analyses indicated that LP4 and LP5 had the highest non-ED-related psychopathology.

DISCUSSION

These findings indicate that there is substantial variability in the phenomenology of traditional DSM-based ED categories across latent profiles, and highlight the salience of certain ED phenotypes that have been debated in the literature. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:542-550).

Rethinking Thought Disorder

It has been 30 years since Holzman introduced a special issue of the Schizophrenia Bulletin entitled “Thought Disorder in Schizophrenia.” He pointed out in his Editor’s Introduction that in contrast to the explosion of interest at that time in the biological aspects of schizophrenia, there were important areas of study that represented “... relatively neglected aspects of the psychopathology of schizophrenia, namely the varieties of thinking disorders (emphasis added) characteristic of schizophrenic patients and their possible underlying mechanisms.” Perhaps presciently, he ended his introduction by expressing hope that the articles included in that issue would lead to further intensive study of the cognitive (emphasis added) dysfunctions in schizophrenia. There has, indeed, been extensive research conducted in further understanding cognitive dysfunctions in schizophrenia, but considerably less so in understanding thought disorder.

McLean OnTrack: a transdiagnostic program for early intervention in first-episode psychosis

AIMS

Most programs specializing in the treatment of first-episode psychosis in the United States focus on schizophrenia. However, many early psychosis patients do not fit into this diagnostic category. Here we describe McLean OnTrack, an intensive outpatient treatment program that accepts all comers with first-episode psychosis.

METHODS

We assessed baseline characteristics of patients in the 2.5 years since program initiation. We examined how initial referral diagnoses compare with current diagnoses, calculating the proportion of diagnostic changes.

RESULTS

At 2.5 years, patients in McLean OnTrack consist of 30 (33.0%) individuals with primary psychotic disorder, 40 (44.0%) with affective psychosis, 19 (20.9%) with psychotic disorder not otherwise specified (NOS) who do not meet full criteria for either category and two (2.2%) individuals with no psychosis. Although patients with affective psychosis had higher pre-morbid functioning, all three categories of psychosis had similar rates of prior hospitalizations and substance use. The retention rate in the psychotic disorder NOS group was lower than that in affective and primary psychotic disorders. Finally, diagnoses changed over the course of treatment in 50.5% of patients.

CONCLUSIONS

Diagnostic heterogeneity appears to be the norm among patients with first-episode psychosis, and diagnoses commonly evolve over the illness course. Baseline indices of illness severity were similar across categories and suggest the need for early intervention, irrespective of specific diagnosis. We discuss the benefits and challenges of a transdiagnostic approach to early intervention in first-episode psychosis, treating patients who share many but not all characteristics.

Are the bipolar disorders best modelled categorically or dimensionally?

OBJECTIVE

Considerable debate exists as to whether the bipolar disorders are best classified according to a categorical or dimensional model. This study explored whether there is evidence for a single or multiple subpopulations and the degree to which differing diagnostic criteria correspond to bipolar subpopulations.

METHOD

A mixture analysis was performed on 1081 clinically diagnosed (and a reduced sample of 497 DSM-IV diagnosed) bipolar I and II disorder patients, using scores on hypomanic severity (as measured by the Mood Swings Questionnaire). Mixture analyses were conducted using two differing diagnostic criteria and two DSM markers to ascertain the most differentiating and their associated clinical features.

RESULTS

The two subpopulation solution was most supported although the entropy statistic indicated limited separation and there was no distinctive point of rarity. Quantification by the odds ratio statistic indicated that the clinical diagnosis (respecting DSM-IV criteria, but ignoring 'high' duration) was somewhat superior to DSM-IV diagnosis in allocating patients to the putative mixture analysis groups. The most differentiating correlate was the presence or absence of psychotic features.

CONCLUSION

Findings favour the categorical distinction of bipolar I and II disorders and argue for the centrality of the presence or absence of psychotic features to subgroup differentiation.

Characterizing a psychiatric symptom dimension related to deficits in goal-directed control

Prominent theories suggest that compulsive behaviors, characteristic of obsessive-compulsive disorder and addiction, are driven by shared deficits in goal-directed control, which confers vulnerability for developing rigid habits. However, recent studies have shown that deficient goal-directed control accompanies several disorders, including those without an obvious compulsive element. Reasoning that this lack of clinical specificity might reflect broader issues with psychiatric diagnostic categories, we investigated whether a dimensional approach would better delineate the clinical manifestations of goal-directed deficits. Using large-scale online assessment of psychiatric symptoms and neurocognitive performance in two independent general-population samples, we found that deficits in goal-directed control were most strongly associated with a symptom dimension comprising compulsive behavior and intrusive thought. This association was highly specific when compared to other non-compulsive aspects of psychopathology. These data showcase a powerful new methodology and highlight the potential of a dimensional, biologically-grounded approach to psychiatry research.

DOI:http://dx.doi.org/10.7554/eLife.11305.001

When an individual resists the temptation to stay out late in order to get a good night’s sleep, he or she is exercising what is known as “goal-directed control”. This kind of control allows individuals to regulate their behaviour in a deliberate manner. It is thought that a reduction in goal-directed control may be linked to compulsiveness or compulsivity, a psychological trait that involves excessive repetition of thoughts or actions. Furthermore, evidence shows that goal-directed control is reduced in people with compulsive disorders, such as obsessive-compulsive disorder (or OCD) and drug addiction. However, failures of goal-directed control have also been reported in other mental health conditions that are not linked to compulsivity, such as social anxiety disorder.

The fact that reduced goal-directed control is found across various mental health conditions highlights a core issue in modern psychiatric research and treatment. Mental health conditions are typically defined and diagnosed by their clinical symptoms, not by their underlying psychological traits or biological abnormalities. This makes it difficult to determine the cause of a specific disorder, as its symptoms are often rooted in the same psychological and biological traits seen in other mental health conditions.

To start to tackle this issue, Gillan et al. used a strategy that allowed them to look at compulsivity as a “trans-diagnostic dimension”; that is, as something that exists on a spectrum and is not specific to one disorder but involved in numerous different mental health conditions. Nearly 2,000 people completed an online task that assessed goal-directed control, and filled in questionnaires that measured symptoms of various mental health conditions. Gillan et al. showed that, as expected, people with reduced goal-directed control were generally more compulsive, and that this relationship could be seen in the context of both OCD and other compulsive disorders such as addiction.

Further, by leveraging the efficiency of online data collection to collect such a large sample, Gillan et al. were also able to examine how much different symptoms co-occurred in people. This enabled them to use a statistical technique to pick out three trans-diagnostic dimensions – compulsive behaviour and intrusive thought, anxious-depression and social withdrawal – and found that only the compulsive factor was associated with reduced goal-directed control. In fact, reduced goal-directed control was found to be more closely related to compulsivity than the symptoms of traditional mental health disorders including OCD. These findings show that research into the causes of mental health conditions and perhaps ultimately diagnosis and treatment – all of which have traditionally approached specific disorders in isolation – would benefit greatly from a trans-diagnostic approach.

DOI:http://dx.doi.org/10.7554/eLife.11305.002

Clinical Implications of a Dimensional Approach: The Normal:Abnormal Spectrum of Early Irritability

OBJECTIVE

The importance of dimensional approaches is widely recognized, but an empirical base for clinical application is lacking. This is particularly true for irritability, a dimensional phenotype that cuts across many areas of psychopathology and manifests early in life. We examine longitudinal, dimensional patterns of irritability and their clinical import in early childhood.

METHOD

Irritability was assessed longitudinally over an average of 16 months in a clinically enriched, diverse community sample of preschoolers (N = 497; mean = 4.2 years; SD = 0.8). Using the Temper Loss scale of the Multidimensional Assessment Profile of Disruptive Behavior (MAP-DB) as a developmentally sensitive indicator of early childhood irritability, we examined its convergent/divergent, clinical, and incremental predictive validity, and modeled its linear and nonlinear associations with clinical risk.

RESULTS

The Temper Loss scale demonstrated convergent and divergent validity to child and maternal factors. In multivariate analyses, Temper Loss predicted mood (separation anxiety disorder [SAD], generalized anxiety disorder [GAD], and depression/dysthymia), disruptive (oppositional defiant disorder [ODD], attention-deficit/hyperactivity disorder [ADHD], and conduct disorder [CD]) symptoms. Preschoolers with even mildly elevated Temper Loss scale scores showed substantially increased risk of symptoms and disorders. For ODD, GAD, SAD, and depression, increases in Temper Loss scale scores at the higher end of the dimension had a greater impact on symptoms relative to increases at the lower end. Temper Loss scale scores also showed incremental validity over DSM-IV disorders in predicting subsequent impairment. Finally, accounting for the substantial heterogeneity in longitudinal patterns of Temper Loss significantly improved prediction of mood and disruptive symptoms.

CONCLUSION

Dimensional, longitudinal characterization of irritability informs clinical prediction. A vital next step will be empirically generating parameters for the incorporation of dimensional information into clinical decision-making with reasonable certainty.

Are personality disorder dimensions related over time? An examination over the course of ten years using multivariate growth modeling

OBJECTIVE

Despite the well-documented literature on cross-sectional comorbidity, there is a paucity of data on the associations between personality disorders (PDs) over time. Using multivariate growth modeling, the present study examined the inter-relationships between pairs of PD disorder dimensions.

METHODS

We tested these associations in a sample of 142 depressed outpatients followed-up five times over the course of 10 years.

RESULTS

We found cross-sectional associations between the initial levels of severity of many pairs of PD dimensions. However, there was limited support for longitudinal associations between PD dimensions.

CONCLUSION

These findings suggest that the course of PD dimensions is fairly independent of each other, and that initial levels of PD dimensions have relatively little prognostic value for predicting the course of other PD dimensions.

Shared dimensions of performance and activation dysfunction in cognitive control in females with mood disorders

Major depressive disorder and bipolar disorder share symptoms that may reflect core mood disorder features. This has led to the pursuit of intermediate phenotypes and a dimensional approach to understand neurobiological disruptions in mood disorders. Executive dysfunction, including cognitive control, may represent a promising intermediate phenotype across major depressive disorder and bipolar disorder. This study examined dimensions of cognitive control in women with major depressive disorder or bipolar disorder in comparison to healthy control subjects using two separate, consecutive experiments. For Experiment 1, participants completed a behavioural cognitive control task (healthy controls = 150, major depressive disorder = 260, bipolar disorder = 202; age range 17-84 years). A sample of those participants (healthy controls = 17, major depressive disorder = 19, and bipolar disorder = 16) completed a similar cognitive control task in an event-related design functional magnetic resonance imaging protocol for Experiment 2. Results for Experiment 1 showed greater impairments on the cognitive control task in patients with mood disorders relative to healthy controls (P < 0.001), with more of those in the mood disorder group falling into the 'impaired' range when using clinical cut-offs (<5th percentile). Experiment 2 revealed only a few areas of shared activation differences in mood disorder greater than healthy controls. Activation analyses using performance as a regressor, irrespective of diagnosis, revealed within and extra-network areas that were more active in poor performers. In summary, performance and activation during cognitive control tasks may represent an intermediate phenotype for mood disorders. However, cognitive control dysfunction is not uniform across women with mood disorders, and activation is linked to performance more so than disease. These findings support subtype and dimensional approaches to understanding risk and expression of mood disorders and are a promising area of inquiry, in line with the Research Domain Criteria initiative of NIMH.

Dimensional psychiatry: reward dysfunction and depressive mood across psychiatric disorders

RATIONALE

A dimensional approach in psychiatry aims to identify core mechanisms of mental disorders across nosological boundaries.

OBJECTIVES

We compared anticipation of reward between major psychiatric disorders, and investigated whether reward anticipation is impaired in several mental disorders and whether there is a common psychopathological correlate (negative mood) of such an impairment.

METHODS

We used functional magnetic resonance imaging (fMRI) and a monetary incentive delay (MID) task to study the functional correlates of reward anticipation across major psychiatric disorders in 184 subjects, with the diagnoses of alcohol dependence (n = 26), schizophrenia (n = 44), major depressive disorder (MDD, n = 24), bipolar disorder (acute manic episode, n = 13), attention deficit/hyperactivity disorder (ADHD, n = 23), and healthy controls (n = 54). Subjects' individual Beck Depression Inventory-and State-Trait Anxiety Inventory-scores were correlated with clusters showing significant activation during reward anticipation.

RESULTS

During reward anticipation, we observed significant group differences in ventral striatal (VS) activation: patients with schizophrenia, alcohol dependence, and major depression showed significantly less ventral striatal activation compared to healthy controls. Depressive symptoms correlated with dysfunction in reward anticipation regardless of diagnostic entity. There was no significant correlation between anxiety symptoms and VS functional activation.

CONCLUSION

Our findings demonstrate a neurobiological dysfunction related to reward prediction that transcended disorder categories and was related to measures of depressed mood. The findings underline the potential of a dimensional approach in psychiatry and strengthen the hypothesis that neurobiological research in psychiatric disorders can be targeted at core mechanisms that are likely to be implicated in a range of clinical entities.

On the latent structure of problem gambling: a taxometric analysis

AIMS

To test whether problem gambling is a categorical or dimensional disorder on the basis of two problem gambling assessments. This distinction discriminates between two different conceptualizations of problem gambling: one that problem gambling is defined by its addictive properties, the other that it is a continuum of harm.

METHOD

Using The British Gambling Prevalence Survey 2010, a nationally representative sample of the United Kingdom conducted by the National Centre for Social Research, five different taxometric analyses were carried out on cases from two problem gambling screens: the Problem Gambling Severity Index (PGSI) and a measure derived from the DSM-IV Pathological Gambling criteria. Two further analyses were conducted on the total scores for these measures.

RESULTS

There was strong evidence that both scales were measuring a categorical construct. Fit indices consistently supported a categorical interpretation [comparison curve fit index (CCFI) > 0.6]. The PGSI analysis indicated the presence of a taxon (CCFIs = 0.633, 0.756). The analysis conducted on the adapted DSM-IV criteria indicated stronger quantitative support for a taxon (CCFIs = 0.717, 0.811 and 0.756) but items probing a loss of control were inconsistent. The taxometric analyses of both scales support a categorical interpretation (CCFIs = 0.628, 0.567), but extreme caution should be used due to high nuisance covariance.

CONCLUSIONS

Two problem gambling screens (the Problem Gambling Severity Index and a measure derived from the DSM-IV Pathological Gambling criteria) appear to measure a categorical construct that taps into a categorical, loss of control model of problem gambling. There is some evidence that the two screens measure different aspects of an addiction construct.

Dimensional models of personality: the five-factor model and the DSM-5

It is evident that the classification of personality disorder is shifting toward a dimensional trait model and, more specifically, the five-factor model (FFM). The purpose of this paper is to provide an overview of the FFM of personality disorder. It will begin with a description of this dimensional model of normal and abnormal personality functioning, followed by a comparison with a proposal for future revisions to DSM-5 and a discussion of its potential advantages as an integrative hierarchical model of normal and abnormal personality structure.

Advancing a multidimensional, developmental spectrum approach to preschool disruptive behavior

OBJECTIVE

Dimensional approaches are gaining scientific traction. However, their potential for elucidating developmental aspects of psychopathology has not been fully realized. The goal of this article is to apply a multidimensional, developmental framework to model the normal-abnormal spectrum of preschool disruptive behavior. The Multidimensional Assessment of Preschool Disruptive Behavior (MAP-DB), a novel measure, was used to model dimensional severity across developmental parameters theorized to distinguish the normative misbehavior of early childhood from clinically salient disruptive behavior. The 4 MAP-DB dimensions are Temper Loss, Noncompliance, Aggression, and Low Concern for Others.

METHOD

Parents of a diverse sample of 1,488 preschoolers completed the MAP-DB. Multidimensional item response theory (IRT) was used for dimensional modeling.

RESULTS

The 4-dimensional, developmentally informed model demonstrated excellent fit. Its factor loadings did not differ across demographic subgroups. All dimensions provided good coverage of the abnormal end of the severity continuum, but only Temper Loss and Noncompliance provided good coverage of milder, normatively occurring behaviors. The developmental expectability and quality of behaviors distinguished normative from atypical behaviors. The point at which frequency of behaviors was atypical varied based on dimensional location for Temper Loss, Noncompliance, and Aggression.

CONCLUSION

The MAP-DB provides an innovative method for operationalizing developmentally specified, dimensional phenotypes in early childhood. Establishing the validity of these dimensional phenotypes in relation to clinical outcomes, neurocognitive substrates, and etiologic pathways will be a crucial test of their clinical utility.

An item response theory integration of normal and abnormal personality scales

The Diagnostic and Statistical Manual of Mental Disorders (DSM–IV–TR) currently conceptualizes personality disorders (PDs) as categorical syndromes that are distinct from normal personality. However, an alternative dimensional viewpoint is that PDs are maladaptive expressions of general personality traits. The dimensional perspective postulates that personality pathology exists at a more extreme level of the latent trait than does general personality. This hypothesis was examined using item response theory analyses comparing scales from two personality pathology instruments—the Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ; Livesley & Jackson, in press) and the Schedule for Nonadaptive and Adaptive Personality (SNAP; Clark, 1993; Clark, Simms, Wu, & Casillas, in press)—with scales from an instrument designed to assess normal range personality, the NEO Personality Inventory–Revised (NEO PI-R; Costa & McCrae, 1992). The results indicate that respective scales from these instruments assess shared latent constructs, with the NEO PI-R providing more information at the lower (normal) range and the DAPP-BQ and SNAP providing more information at the higher (abnormal) range. Nevertheless, the results also demonstrated substantial overlap in coverage. Implications of the findings are discussed with respect to the study and development of items that would provide specific discriminations along underlying trait continua.

Biological substrates underpinning diagnosis of major depression

Major depression is characterized by low mood, a reduced ability to experience pleasure and frequent cognitive, physiological and high anxiety symptoms. It is also the leading cause of years lost due to disability worldwide in women and men, reflecting a lifelong trajectory of recurring episodes, increasing severity and progressive treatment resistance. Yet, antidepressant drugs at best treat only one out of every two patients and have not fundamentally changed since their discovery by chance >50 yr ago. This status quo may reflect an exaggerated emphasis on a categorical disease classification that was not intended for biological research and on oversimplified gene-to-disease models for complex illnesses. Indeed, genetic, molecular and cellular findings in major depression suggest shared risk and continuous pathological changes with other brain-related disorders. So, an alternative is that pathological findings in major depression reflect changes in vulnerable brain-related biological modules, each with their own aetiological factors, pathogenic mechanisms and biological/environment moderators. In this model, pathological entities have low specificity for major depression and instead co-occur, combine and interact within individual subjects across disorders, contributing to the expression of biological endophenotypes and potentially clinical symptom dimensions. Here, we discuss current limitations in depression research, review concepts of gene-to-disease biological scales and summarize human post-mortem brain findings related to pyramidal neurons, γ-amino butyric acid neurons, astrocytes and oligodendrocytes, as prototypical brain circuit biological modules. Finally we discuss nested aetiological factors and implications for dimensional pathology. Evidence suggests that a focus on local cell circuits may provide an appropriate integration point and a critical link between underlying molecular mechanisms and neural network dysfunction in major depression.