Patterns of comorbidity among mental disorders: a person-centered approach

Identifying internalizing transdiagnostic profiles through motivational and cognitive control systems: Relations with symptoms, functionality, and quality of life

BACKGROUND

The diversity of patients' symptomatology among people seeking treatment on community-based mental health services poses significant challenges to traditional models of care. Recent approaches favor identifying transdiagnostic factors that allow a better understanding of patient heterogeneity and designing more effective and quality interventions. This study examines the heterogeneity of patients with internalizing symptoms based on profiles identified with cognitive and motivational control variables. Differences between these profiles on dimensional measures of psychopathology and quality of life are examined.

METHODS

263 patients were selected by non-probabilistic sampling procedures on mental health services in the province of Huelva (Spain). A latent class analysis on the standardized scale scores of The Behavioral Inhibition/Behavioral Activation System Scales and the Effortful Control Scale of the Adult Temperament Questionnaire Short-Form was conducted. Profiles were compared on the scores of the Inventory of Depression and Anxiety Symptoms-II, the WHO Disability Assessment Schedule II, and the Health Assessment Questionnaire SF-36.

RESULTS

The four latent profile solution is the one that showed the best fit indicators and substantive interpretability, with a kappa of 0.94 in the cross-validation procedure with 75% of the sample. No sex differences were found between the profiles (χ32 5.17, p = .160). Profiles #1 and #3, both characterized by an imbalance between low activation and high inhibition, had lower well-being, lower functionality, and quality of life. When comparing profile #2 (featuring the highest inhibitory control) lower scores on most internalizing scales are observed, specially claustrophobia, social anxiety, panic mania. Profile #4 (low control, high activation, and high inhibition) showed greater scores on both mania and euphoria and lower scores on emotional role.

CONCLUSIONS

We identified four distinctive profiles that had overly increased behavioral inhibition (as expected in internalizing disorders) and differed in the degree of imbalance between inhibition and activation systems, and between motivational systems and top-down cognitive control. The profile characterized by high activation and reduced cognitive (inhibitory) control was the one showing greater mood-related symptoms and lower levels of quality of life. These profiles could be generated by treatment providers to guide clinical management in an evidence-based manner.

The validity of transdiagnostic factors in predicting homotypic and heterotypic continuity of psychopathology symptoms over time

Studies of the continuity of psychopathology symptoms mainly involved the traditional conceptualization that mental disorders are discrete entities. However, high comorbidity rates suggest a few transdiagnostic factors that underlie individual disorders. Therefore, the present study examined the validity of transdiagnostic factors in predicting homotypic and heterotypic continuity of comorbidity classes across two waves in a nationally representative sample. We conducted a latent transition analysis to investigate how transdiagnostic factors differentially affect the transition probabilities of comorbidity classes across time. Results found a notable predictive validity of transdiagnostic factors: (a) internalizing strongly predicted the stability of the internalizing class and transition from the externalizing class to internalizing class, and (b) externalizing predicted the transition from the internalizing class to externalizing class. The study also found a more dynamic prediction pattern leading to equifinality and multifinality of psychopathology symptoms. The findings suggest that transdiagnostic factors can provide information on how individuals' symptom manifestations change over time, highlighting the potential benefits of incorporating transdiagnostic factors into assessment, treatment, and prevention.

A pilot study of new approaches to exploring illness trajectories and patterns of comorbidity in major mental disorders

AIMS

We explored lifetime comorbidities in clinical subsamples with a diagnosis of Psychosis (N = 143), bipolar (BD = 511), and unipolar disorders (UP = 861).

METHODS

We analyzed trajectories and patterns of comorbidities using novel metrics, namely bubble plots and density of antecedent events per year of illness exposure per individual.

RESULTS

Age at onset (AAO) of most comorbidities was similar to epidemiological studies, but cumulative rates were higher in clinical cases. There were some between group differences in patterns or burden of comorbidities, for example, Psychosis showed the earliest AAO of any mental disorder; UP showed the latest AAO of the index diagnosis. The relative risk of multimorbidity was lower in UP compared with other diagnoses, however, the goodness of fit for the illness trajectory path was lowest for BD.

CONCLUSIONS

Bubble plots offer a useful representation of timing, sequence, cumulative probability and of comorbidities, the added value of reporting density measures was less obvious.

Psychosocial Profiles of Patients Admitted to Psychiatric Emergency Services: Results from the Signature Biobank Project

OBJECTIVES

Patients admitted to psychiatric emergency services (PES) are highly heterogenous. New tools based on a transdiagnosis approach could help attending psychiatrists in their evaluation process and treatment planning. The goals of this study were to: (1) identify profiles of symptoms based on self-reported, dimensional outcomes in psychiatric patients upon their admission to PES, (2) link these profiles to developmental variables, that is, history of childhood abuse (CA) and trajectories of externalizing behaviours (EB), and (3) test whether this link between developmental variables and profiles was moderated by sex.

METHODS

In total, 402 patients were randomly selected from the Signature Biobank, a database of measures collected from patients admitted to the emergency of a psychiatric hospital. A comparison group of 92 healthy participants was also recruited from the community. Symptoms of anxiety, depression, alcohol and drug abuse, impulsivity, and psychosis as well as CA and EB were assessed using self-reported questionnaires. Symptom profiles were identified using cluster analysis. Prediction of profile membership by sex, CA, and EB was tested using structural equation modelling.

RESULTS

Among patients, four profiles were identified: (1) low level of symptoms on all outcomes, (2) high psychotic symptoms, (3) high anxio-depressive symptoms, and (4) elevated substance abuse and high levels of symptoms on all scales. An indirect effect of CA was found through EB trajectories: patients who experienced the most severe form of CA were more likely to develop chronic EB from childhood to adulthood, which in turn predicted membership to the most severe psychopathology profile. This indirect effect was not moderated by sex.

CONCLUSION

Our results suggest that a transdiagnostic approach allows to highlight distinct clinical portraits of patients admitted to PES. Importantly, developmental factors were predictive of specific profiles. Such transdiagnostic approach is a first step towards precision medicine, which could lead to develop targeted interventions.

Protective and Risk Factors at the Intersection of Chronic Pain, Depression, Anxiety, and Somatic Amplification: A Latent Profile Approach

Objective

Research indicates a complex nexus between chronic pain, depression, anxiety, and somatic amplification (PDAS) symptoms, marked by high rates of co-morbidity and mutually maintaining mechanisms. Although recent frameworks have attempted to explain co-occurrence rates of pain and other comorbid disorders, the interrelations between PDAS and their impacts on pain outcomes have not been adequately examined with a person-centered approach. Using nationally representative data, this study assessed the heterogeneity in PDAS symptomatology and examined links among risk and protective factors in different profiles.

Methods

Data were derived from 1027 participants in the National Survey of Midlife Development in the United States (MIDUS) who completed telephone interviews or self-report measures that assessed PDAS, various sources of social supports (family, friends, spouses/partners, religion, coworkers, and supervisors), and the number of healthcare visits.

Results

We found heterogeneity in symptom severity rather than symptom type across classes over time. Regardless of comorbidity severity, people reported similar levels of somatic symptoms, which may help clinicians more effectively diagnose comorbidity issues among chronic pain patients. As PDAS symptomatology increased by group, the perceived levels of social support decreased. Membership in a higher symptom severity class was associated with being female, younger age, and an increase in medical, but not mental health visits.

Limitations

Limitations included the use of a cross-sectional design, reliance on self-report measures, and a sample largely comprised of Whites.

Conclusion

PDAS co-occurs across classes, which may relate to shared risk and protective factors. This study lays the foundation to investigate similar questions for overlapping symptoms that occur during the same period, which would shed light on whether—among middle to older age adults—these disorders are attributable to a common mechanism and if they may inform transdiagnostic treatments.

Using density of antecedent events and trajectory path analysis to investigate family-correlated patterns of onset of bipolar I disorder: a comparison of cohorts from Europe and USA

BACKGROUND

Major contributors to the global burden of bipolar disorders (BD) are the early age at onset (AAO) and the co-occurrence of non-mood disorders before and after the onset of BD. Using data from two independent cohorts from Europe and the USA, we investigated whether the trajectories of BD-I onset and patterns of psychiatric comorbidities differed in (a) individuals with or without a family history (FH) of BD, or (b) probands and parents who both had BD-I.

METHODS

First, we estimated cumulative probabilities and AAO of comorbid mental disorders in familial and non-familial cases of BD-I (Europe, n = 573), and sex-matched proband-parent pairs of BD-I cases (USA, n = 194). Then we used time to onset analyses to compare overall AAO of BD-I and AAO according to onset polarity. Next, we examined associations between AAO and polarity of onset of BD-I according to individual experiences of comorbidities. This included analysis of the density of antecedent events (defined as the number of antecedent comorbidities per year of exposure to mental illness per individual) and time trend analysis of trajectory paths plotted for the subgroups included in each cohort (using R² goodness of fit analysis).

RESULTS

Earlier AAO of BD-I was found in FH versus non-FH cases (log rank test = 7.63; p = 0.006) and in probands versus parents with BD-I (log rank test = 15.31; p = 0.001). In the European cohort, AAO of BD-I was significantly associated with factors such as: FH of BD (hazard ratio [HR]: 0.60), earlier AAO of first non-mood disorder (HR: 0.93) and greater number of comorbidities (HR: 0.74). In the USA cohort, probands with BD-I had an earlier AAO for depressive and manic episodes and AAO was also associated with e.g., number of comorbidities (HR: 0.65) and year of birth (HR: 2.44). Trajectory path analysis indicated significant differences in density of antecedents between subgroups within each cohort. However, the time trend R² analysis was significantly different for the European cohort only.

CONCLUSIONS

Estimating density of antecedent events and comparing trajectory plots for different BD subgroups are informative adjuncts to established statistical approaches and may offer additional insights that enhance understanding of the evolution of BD-I.

Attachment to Pets Moderates Transitions in Latent Patterns of Mental Health Following the Onset of the COVID-19 Pandemic: Results of a Survey of U.S. Adults

This cross-sectional study examined whether, and to what extent, attachment to pets was associated with changes in latent patterns of adults' perceived mental health symptoms during the COVID-19 pandemic (n = 1942). We used latent transition analysis to determine the stability of subgroup membership pre- and post-COVID and the effect of attachment to pets on transition probabilities. Mental health before COVID-19 was measured retrospectively. Five subgroups were identified: low symptoms, mild symptoms, moderate symptoms, high symptoms, and severe symptoms. Among individuals in the moderate and high symptoms subgroups, those who reported high attachment to pets generally had greater odds of transitioning to a less severe symptom profile (OR = 2.12) over time than those with low attachment to pets (OR = 1.39). However, those who had a severe symptom profile and high attachment to pets had lower odds of transitioning to a less severe symptom profile (OR = 0.30) and higher odds of maintaining a severe symptom profile (OR = 3.33) than those with low attachment to pets. These findings suggest that the protective and risk effects of attachment to pets differ based on individuals' psychological symptom patterns across multiple indicators. We discuss the implications of these findings for research, policy, and practice.

A latent class analysis of alcohol and posttraumatic stress symptoms among offspring of parents with and without alcohol use disorder

The co-occurrence of posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) is widely known, yet few studies have examined whether and how AUD symptoms co-occur with PTSD symptom clusters of hypervigilance, avoidance/numbing, and re-experiencing. The purpose of this study was to examine potential overlap between AUD and posttraumatic stress symptomatology, and to characterize the resultant latent classes in terms of demographics, drinking behaviors, parental AUD, and specific traumas experienced (physical violence, sexual violence, and non-assaultive trauma). We hypothesized that classes would be differentiated by type and severity of AUD and PTS symptoms. Drawing from a sample of white and Black participants from the Collaborative Study on the Genetics of Alcoholism (COGA), we examined young adults between the ages of 18-35 who had experienced trauma (N = 2478). A series of LCA models based on the type of trauma experienced, posttraumatic stress symptoms and problematic alcohol use were then fitted to the data. A four-class solution provided the best fit, consisting of a low symptom class (N = 1134), moderate alcohol/low PTS severity (N = 623), mild alcohol/high PTS severity (N = 544), and high symptom severity (N = 177). Higher prevalence of sexual assault was associated with membership in high PTS severity classes, and parent AUD was associated with membership in each class, particularly when the mother or both parents had the disorder. Using person-centered methods such as LCA is a commonsense approach to understanding the heterogeneity of symptoms, trauma types, and individual-level characteristics associated with trauma-exposed individuals and comorbid AUD-PTSD, and our study is one of relatively few to empirically ascertain the co-occurrence of alcohol and PTS symptoms in a high-risk family sample.

Adolescent Resting-State Brain Networks and Unique Variability of Conduct Problems Within the Externalizing Dimension

The externalizing psychopathological dimension is associated with alterations in adolescents' functional brain connectivity. The current study aims to identify the functional correlates of the unique variability in conduct problems within the context of the broad externalizing dimension. The broad externalizing dimension and unique variability in conduct problems were estimated using a bifactor model. Resting-state data were available for a sample of 125 adolescents. Based on multiresolution parcellation of functional brain networks atlas, major resting-state functional brain networks and the connectivity correlates of unique conduct problems and the broad externalizing dimension were established. The broad externalizing dimension was related to connectivity alterations in the ventral attention/salience network, while unique variability in conduct problems dimension was related to connectivity alterations in the cerebellum crusi as well as the mesolimbic network. The current study is a first step toward the identification of functional resting-state network correlates of broad and specific variability in the externalizing dimension.

The prevalence of mental disorders and patterns of comorbidity within a large sample of mentally ill prisoners: A network analysis

BACKGROUND

Comorbidity has profound implications in both the clinical field and research, yet little is known about the prevalence and structure of comorbid mental disorders. This article aims not only to present data on the prevalence of mental disorders and comorbidity, but also to explore relationships between comorbid mental disorders by using a network approach.

METHODS

Data used in this cross-sectional study are part of a prospective cohort study within penitentiary psychiatric centers (PPCs) in the Netherlands. It includes DSM diagnoses of 5,257 unique male patients incarcerated in one of the PPC's. Prevalence rates of mental disorders and comorbidity were calculated, the network of comorbid DSM diagnoses was constructed using regression coefficients.

RESULTS

Schizophrenia spectrum and substance-related disorders were most prevalent within this sample (56.7 and 43.1%, respectively), and over half of all patients were diagnosed with a comorbid disorder (56.9%). Four distinctive groups of disorders emerged from the network analysis of DSM diagnoses: substance use, impulsivity, poor social skills, and disruptive behaviors. Psychotic disorders were considered as a separate group as it was unconnected to other disorders.

CONCLUSIONS

Comorbid mental disorders can be described, at least in part, as connected networks. Underlying attributes as well as direct influences of mental disorders on one another seem to be affecting the presence of comorbidity. Results could contribute to the understanding of a possible causal relation between psychopathology and criminal behavior and the development of treatment programs targeting groups of disorders.

Quantifying Dispositional Fear as Threat Sensitivity: Development and Initial Validation of a Model-Based Scale Measure

The Research Domain Criteria initiative aims to reorient the focus of psychopathology research toward biobehavioral constructs that cut across different modalities of measurement, including self-report and neurophysiology. Constructs within the Research Domain Criteria framework are intentionally transdiagnostic, with the construct of "acute threat," for example, broadly relevant to clinical problems and associated traits involving fearfulness and stress reactivity. A potentially valuable referent for research on the construct of acute threat is a structural model of fear/fearlessness questionnaires known to predict variations in physiological threat reactivity as indexed by startle potentiation. The aim of the current work was to develop an efficient, item-based scale measure of the general factor of this structural model for use in studies of dispositional threat sensitivity and its relationship to psychopathology. A self-report scale consisting of 44 items from a conceptually relevant, nonproprietary questionnaire was first developed in a sample of 1,307 student participants, using the general factor of the fear/fearlessness model as a direct referent. This new Trait Fear scale was then evaluated for convergent and discriminant validity with measures of personality and psychopathology in a separate sample (n = 213) consisting of community adults and undergraduate students. The strong performance of the scale in this criterion-validation sample suggests that it can provide an effective means for indexing variations along a dispositional continuum of fearfulness reflecting variations in sensitivity to acute threat.

Tobacco use and the interplay of internalizing, externalizing and substance use problems: A latent class analysis of data from the Population Assessment of Tobacco and Health Study

BACKGROUND

Cigarette smoking is disproportionately high among adults with two or more psychiatric disorders (psychiatric comorbidities), yet research on non-cigarette tobacco use among this population is scant. Additionally, most studies on tobacco use this among this population rely on psychiatric diagnoses rather than individual symptoms, potentially excluding individuals with symptom-specific issues that increase their risk for tobacco use but do not meet the criteria for diagnosis. The objectives of this study were to identify unique classes of individuals based on symptoms of psychiatric disorders and to assess differences in demographic characteristics and tobacco use behaviors between classes.

METHODS

This study used data from Wave 2 of the Population Assessment of Tobacco and Health Study adult dataset. Latent class analysis was used to classify individuals based on internalizing, externalizing and substance use problems. Bivariate and multivariable models examined the association between latent class membership and current use of cigarettes, cigar products, electronic nicotine delivery systems, pipe, hookah and smokeless tobacco products. Poly tobacco use was also examined.

RESULTS

Three latent classes were identified. The "normative" class reported low prevalence of all symptoms, the "severe internalizing and non-violent externalizing" class reported severe internalizing problems and non-violent externalizing problems and the "severe" class reported high prevalence of all symptoms. Tobacco use was highest for the "severe" class and lowest for the "normative" class across products.

CONCLUSIONS

Individuals in the "severe" class may be at elevated risk of tobacco-related morbidity and mortality and would likely benefit from targeted tobacco control interventions.

Comorbidity profile of mental disorders among adolescents: A latent class analysis

The aim of this study was to identify the number of comorbidity profiles among adolescents. Sociodemographic factors associated with the comorbidity profiles were also examined. Latent class analysis was conducted using data from the National Comorbidity Survey Adolescent Supplement (NCS-A), a representative sample of adolescents (N = 10,123) in the United States. Latent classes were derived from 26 lifetime mental disorders which were assessed using the World Health Organization Composite International Diagnostic Instrument (CIDI). A three-class solution provided the best fit for the data, with classes labelled as comorbid emotional disorders (Class I), comorbid behavioural disorders (Class II), and normative (Class III). Class I (15.62% of the participants) included adolescents with a high probability of having anxiety, depressive, and intermittent explosive disorder. Class II (6.97%) was characterised by adolescents with a high probability of having substance use, behavioural disorders, and major depression. Class III (77.41%) was characterised by adolescents with a low probability of having any mental disorders. Characterising comorbid profile of mental disorders using person-based approach yields a higher-order classification that could have important clinical implications.

Heterogeneity in the Co-occurrence of Substance Use and Posttraumatic Stress Disorder: A Latent Class Analysis Approach

Objective: Posttraumatic stress disorder (PTSD) often co-occurs with substance use (SU). Although there has been independent research on subgroups of participants based on their PTSD or SU responses, rarely are PTSD-SU typologies examined consistent with a precision medicine approach (and corresponding person-centered statistical approaches). The current study examined the nature and construct validity (covariates of depression, physical aggression, verbal aggression, anger, hostility, reckless and self-destructive behaviors [RSDB]) of the best-fitting latent class solution in categorizing participants based on PTSD (PTSD Checklist for DSM-5) and alcohol/drug use responses (Alcohol Use and Disorders Identification Test Alcohol Consumption Questions, Drug Abuse Screening Test). Methods: The sample included 375 trauma-exposed participants recruited from Amazon's Mechanical Turk online labor market. Results: Latent class analyses indicated an optimal three-class solution (low PTSD/SU, moderate PTSD/drug and high alcohol, and high PTSD/SU). Multinomial logistic regressions indicated that depression (OR = 1.22) and frequency of RSDBs (OR = 1.20) were significant predictors of the moderate PTSD/drug and high alcohol class versus the low PTSD/SU class. Depression (OR = 1.55) and frequency of RSDBs (OR = 1.19) were significant predictors of the high PTSD/SU class versus the low PTSD/SU class. Only depression (OR = 1.27) was a significant predictor of the high PTSD/SU class versus the moderate PTSD/drug and high alcohol class. Conclusions: Results provide construct validity support for three meaningful latent classes with unique relations with depression and RSDBs. These findings improve our understanding of heterogeneous PTSD-SU comorbidity patterns and highlight acknowledgment of such subtyping (subgrouping) in considering differential treatment options, treatment effectiveness, and resource allocation.

Psychopathy and Internalizing Psychopathology: A Triarchic Model Perspective

Methodological and conceptual differences across studies have impeded our understanding of the relationship between psychopathy and internalizing psychopathology. To shed further light on this question, we undertook correlational and structural-modeling analyses of data from two samples to characterize how facets of psychopathy relate to internalizing psychopathology when assessed using multidimensional measures of each construct (i.e., Triarchic Psychopathy Measure, Inventory of Depression and Anxiety Symptoms). Participants for Study 1 were 470 undergraduates and community-dwelling adults who completed these measures in self-report form; participants for Study 2 were 301 community-dwelling adults who completed informant-rating versions of these measures (as applied to a known-other). Across samples, analyses revealed sharply contrasting associations for the three triarchic-model facets with internalizing psychopathology and its subdomains, with boldness relating negatively in most cases, disinhibition relating positively in most cases, and meanness exhibiting mostly null associations. Results provide a nuanced picture of associations between psychopathic symptomatology and internalizing problems.

Biobehavioral threat sensitivity and amygdala volume: A twin neuroimaging study

Current literature on the relationship between dispositional fear (or threat sensitivity) and amygdala gray matter volume (GMV) is heterogeneous, with findings including positive, negative, and null correlations. A clearer understanding of this relationship would help to determine the potential utility of amygdala volume as a biomarker of anxious/depressive (internalizing) disorders and contribute to understanding of neural mechanisms for variations in fearfulness. The study reported here used voxel-based morphometry to quantify amygdala GMV scores from structural neuroimaging data in a sample of 44 monozygotic twins (i.e., 22 pairs). Dispositional threat sensitivity (THT) was quantified using a biobehavioral cross-domain score that combined neurophysiological indicators with a psychological scale measure. Analyses revealed expected high concordance for amygdala GMV between co-twins. With respect to the major question of the study, a negative correlation was found between biobehavioral THT scores and amygdala volume - with individuals higher in THT showing smaller amygdala GMV scores. More modest associations of amygdala GMV with symptoms of social phobia, and fear disorder symptomology more broadly, were mediated by THT. These results provide insight into prior mixed findings and support the combined use of biological and behavioral measures to quantify characteristics relevant to mental health problems.

Translational research in psychiatry: The Research Domain Criteria Project (RDoC)

Despite the consensus achieved in the homogenization of clinical criteria by categorical psychiatric classification systems (DEM and CIE), they are criticized for a lack of validity and inability to guide clinical treatment and research. In this review article we introduce the Research Domain Criteria (RDoC) framework as an alternative framework for translational research in psychiatry. The RDOC framework systematizes both research targets and methodology for research in psychiatry. RDoC is based on a catalogue of neurobiological and neurocognitive evidence of behaviour, and conceives psychopathology as the phenotypic expression of alterations of functional domains that are classified into 5psychobiological systems. The RdoC framework also proposes that domains must be validated with evidence in 7levels of analysis: genes, molecules, cells, nerve circuits, physiology, behaviour and self-reports. As opposed to categorical systems focused on diagnosis, RDoC focuses on the study of psychopathology as a correlate of detectable functional, biological and behavioural disruption of normal processes. In order to build a useful psychiatric nosology for guiding clinical interventions, the RDoC research framework links the neurobiological basis of mental processes with phenotypical manifestations. Although the RDoC findings have not yet been articulated into a specific model for guiding clinical practice, they provide a useful transition system for creating clinical, basic and epidemiological research hypotheses.

Developmental stability of general and specific factors of psychopathology from early childhood to adolescence: dynamic mutualism or p-differentiation?

BACKGROUND

Recent research indicates that the best-fitting structural model of psychopathology includes a general factor capturing comorbidity (p) and several more specific, orthogonal factors. Little is known about the stability of these factors, although two opposing developmental processes have been proposed: dynamic mutualism suggests that symptom-level interaction and reinforcement may lead to a strengthening of comorbidity (p) over time, whereas p-differentiation suggests a general vulnerability to psychopathology that gives way to increasingly distinct patterns of symptoms over time. In order to test both processes, we examine two forms of developmental stability from ages 2 to 14 years: strength (i.e., consistency in the amount of variance explained by general and specific factors) and phenotypic stability (i.e., homotypic and heterotypic continuity).

METHODS

Data are from the NICHD Study of Early Child Care and Youth Development. Psychopathology symptoms were assessed nine times between ages 2 and 14 years (n = 1,253) using the Child Behavior Checklist completed by mothers. Confirmatory bifactor modeling was used to test structural models of psychopathology at each age. Consistency in strength was examined by calculating the Explained Common Variance (ECV) and phenotypic stability was investigated with cross-lagged modeling of the general and specific factors.

RESULTS

Bifactor models fit the data well across this developmental period. ECV values were reasonably consistent across development, with the general factor accounting for the majority of shared variance (61%-71%). Evidence of both homotypic and heterotypic continuity emerged, with most heterotypic continuity involving the general factor, as it both predicted and was predicted by specific factors.

CONCLUSIONS

A bifactor model effectively captures psychopathological comorbidity from early childhood through adolescence. The longitudinal associations between the general and specific factors provide evidence for both the hypothesized processes (dynamic mutualism and p-differentiation) occurring through development.

Extending the Construct Network of Trait Disinhibition to the Neuroimaging Domain: Validation of a Bridging Scale for Use in the European IMAGEN Project

Trait disinhibition, a clinical-liability construct, has well-established correlates in the diagnostic, self-rating, task-behavioral, and brain potential response domains. Recently, studies have begun to test for neuroimaging correlates of this liability factor, but more work of this type using larger data sets is needed to clarify its brain bases. The current study details the development and validation of a scale measure of trait disinhibition composed of questionnaire items available in the IMAGEN project, a large-scale longitudinal study of factors contributing to substance abuse that includes clinical interview, self-report personality, task-behavioral, neuroimaging, and genomic measures. Using a construct-rating and psychometric refinement approach, a scale was developed that evidenced: (a) positive relations with interview-assessed psychopathology in the IMAGEN sample, both concurrently and prospectively and (b) positive associations with scale measures of disinhibition and reported psychopathology, and a robust negative correlation with P3 brain response, in a separate adult sample ( M_age = 19.5). These findings demonstrate that a common scale measure can index this construct from adolescence through to early adulthood, and set the stage for systematic work directed at identifying neural and genetic biomarkers of this key liability construct using existing and future data from the IMAGEN project.

Comorbidity classes and associated impairment, demographics and 9/11-exposures in 8,236 children and adolescents

The extensive comorbidity of psychiatric disorders in children and adolescents leads to clinical heterogeneity, and is an often-overlooked issue in etiopathogenic and treatment studies in developmental psychopathology. In a representative sample (N=8236) of New York City public school students assessed six months after 9/11, latent class analysis was applied to 48 symptoms across seven disorders: posttraumatic stress, agoraphobia, separation anxiety, panic disorder, generalized anxiety (GAD), major depression (MDD) and conduct disorder (CD). Our objective was to identify classes defined by homogenous symptom profiles, and to examine the association between class membership and gender, age, race, different types of exposure to 9/11, and impairment. Eight homogenous comorbidity patterns were identified, including four severe disturbance classes: a multimorbid internalizing class (INT), a class with a high probability of CD, MDD, and GAD symptoms (Distress/EXT), a non-comorbid externalizing class, and a non-comorbid MDD class. Demographic and 9/11-related exposures showed some degree of specificity in their association with severe symptom profiles. Impairment was particularly high in the INT and Distress/EXT classes. A better characterization of phenomic data, that takes comorbidity into account, is essential to understand etiopathogenic processes, and to move psychiatric research forward towards personalized medicine. The high probability of endorsing symptoms of multiple disorders in the INT and Distress/EXT classes supports the use of treatments focusing on multimorbidity. Clinical trials should evaluate the effectiveness of disorder-specific versus transdiagnostic interventions. The association between class membership and demographic and exposure variables suggests that interventions may be improved by considering specific predictors of class membership.

Beyond comorbidity: Toward a dimensional and hierarchical approach to understanding psychopathology across the life span

We propose a novel developmentally informed framework to push research beyond a focus on comorbidity between discrete diagnostic categories and to move toward research based on the well-validated dimensional and hierarchical structure of psychopathology. For example, a large body of research speaks to the validity and utility of the internalizing and externalizing spectra as organizing constructs for research on common forms of psychopathology. The internalizing and externalizing spectra act as powerful explanatory variables that channel the psychopathological effects of genetic and environmental risk factors, predict adaptive functioning, and account for the likelihood of disorder-level manifestations of psychopathology. As such, our proposed theoretical framework uses the internalizing and externalizing spectra as central constructs to guide future psychopathology research across the life span. The framework is particularly flexible, because any of the facets or factors from the dimensional and hierarchical structure of psychopathology can form the focus of research. We describe the utility and strengths of this framework for developmental psychopathology in particular and explore avenues for future research.

Empirically derived patterns of psychiatric symptoms in youth: A latent profile analysis

BACKGROUND

By conceptualizing domains of behavior transdiagnostically, the National Institute of Mental Health Research Domain Criteria (NIMH RDoC) initiative facilitates new ways of studying psychiatric symptoms. In this study, latent profile analysis (LPA) was used to empirically derive classes or patterns of psychiatric symptoms in youth that transect traditional nosologic boundaries.

METHODS

Data were drawn from 509 children and adolescents (ages 7-18 years; mean age =12.9 years; 54% male) who were evaluated in the NIMH Emotion and Development Branch and were heterogeneous with respect to presenting diagnoses and symptoms. Youth and/or their parents completed measures of several core symptom dimensions: irritability, anxiety, depression, and attention deficit hyperactivity disorder (ADHD). LPA was used to parse response patterns into distinct classes, based on the levels of, and interrelations among, scores on the different measures.

RESULTS

Five classes emerged: low levels of symptomatology (52% of sample); anxiety and mild depressive symptoms (17%); parent-reported irritability and ADHD (16%); irritability and mixed comorbid symptoms (10%); and high levels of irritability, anxiety, depression, and ADHD (5%). Importantly, these latent classes cut across informants and the clinical conditions for which youth were initially evaluated. Further, the classes characterized by irritability exhibited the poorest overall functioning.

LIMITATIONS

These data were cross-sectional. Examination of external validators, including neurobiological correlates and symptom course, is warranted.

CONCLUSIONS

Results inform our understanding of the structure of psychiatric symptoms in youth and suggest new ways to operationalize psychopathology and examine it in relation to neurobiology.

Evidence of a prominent genetic basis for associations between psychoneurometric traits and common mental disorders

Threat sensitivity (THT) and weak inhibitory control (or disinhibition; DIS) are trait constructs that relate to multiple types of psychopathology and can be assessed psychoneurometrically (i.e., using self-report and physiological indicators combined). However, to establish that psychoneurometric assessments of THT and DIS index biologically-based liabilities, it is important to clarify the etiologic bases of these variables and their associations with clinical problems. The current work addressed this important issue using data from a sample of identical and fraternal adult twins (N=454). THT was quantified using a scale measure and three physiological indicators of emotional reactivity to visual aversive stimuli. DIS was operationalized using scores on two scale measures combined with two brain indicators from cognitive processing tasks. THT and DIS operationalized in these ways both showed appreciable heritability (0.45, 0.68), and genetic variance in these traits accounted for most of their phenotypic associations with fear, distress, and substance use disorder symptoms. Our findings suggest that, as indices of basic dispositional liabilities for multiple forms of psychopathology with direct links to neurophysiology, psychoneurometric assessments of THT and DIS represent novel and important targets for biologically-oriented research on psychopathology.

Internalizing and externalizing disorders in childhood and adolescence: A latent transition analysis using ALSPAC data

BACKGROUND

Research examining the association between internalizing and externalizing dimensions of psychopathology has relied heavily on variable-centered analytical techniques. Person-centered methodologies complement the variable-centered approach, and may help explain the medium-to-large correlations that exist between higher order dimensions of psychopathology. What little person-centered research exists has been cross-sectional and utilized adult samples. The present study sought to take a person-centered approach to the modeling of psychiatric comorbidity during a key developmental phase; middle childhood through adolescence.

METHODS

Analysis was conducted on data from the Avon Longitudinal Study of Parents and Children (ALSPAC, N=9282). Latent transition analysis (LTA) was conducted using eight DSM-IV disorders assessed at ages 7.5 and 14years as measured indicators.

RESULTS

At both time points, a four class solution provided the best fit, with classes labeled as (i) normative, (ii) primarily internalizing, (iii) primarily externalizing, and (iv) high-risk/multimorbid. There was considerable individual-level stability across time, with approximately 80% of children remaining in the same class at both time points. Those in the internalizing class at baseline were more likely to transition to a less severe class (i.e., the normative class).

CONCLUSIONS

Person-centered methodologies demonstrate that the association between internalizing and externalizing is accounted for by a sub-population at high risk for experiencing psychiatric comorbidity, and 'cross-class' disorders which link the internalizing and externalizing spectra.

A hierarchical causal taxonomy of psychopathology across the life span

We propose a taxonomy of psychopathology based on patterns of shared causal influences identified in a review of multivariate behavior genetic studies that distinguish genetic and environmental influences that are either common to multiple dimensions of psychopathology or unique to each dimension. At the phenotypic level, first-order dimensions are defined by correlations among symptoms; correlations among first-order dimensions similarly define higher-order domains (e.g., internalizing or externalizing psychopathology). We hypothesize that the robust phenotypic correlations among first-order dimensions reflect a hierarchy of increasingly specific etiologic influences. Some nonspecific etiologic factors increase risk for all first-order dimensions of psychopathology to varying degrees through a general factor of psychopathology. Other nonspecific etiologic factors increase risk only for all first-order dimensions within a more specific higher-order domain. Furthermore, each first-order dimension has its own unique causal influences. Genetic and environmental influences common to family members tend to be nonspecific, whereas environmental influences unique to each individual are more dimension-specific. We posit that these causal influences on psychopathology are moderated by sex and developmental processes. This causal taxonomy also provides a novel framework for understanding the heterogeneity of each first-order dimension: Different persons exhibiting similar symptoms may be influenced by different combinations of etiologic influences from each of the 3 levels of the etiologic hierarchy. Furthermore, we relate the proposed causal taxonomy to transdimensional psychobiological processes, which also impact the heterogeneity of each psychopathology dimension. This causal taxonomy implies the need for changes in strategies for studying the etiology, psychobiology, prevention, and treatment of psychopathology. (PsycINFO Database Record

Latent class profile of psychiatric symptoms and treatment utilization in a sample of patients with co-occurring disorders

Objective:

To identify symptom-based subgroups within a sample of patients with co-occurring disorders (CODs) and to analyze intersubgroup differences in mental health services utilization.

Methods:

Two hundred and fifteen patients with COD from an addiction clinic completed the Symptom Checklist 90-Revised. Subgroups were determined using latent class profile analysis. Services utilization data were collected from electronic records during a 3-year span.

Results:

The five-class model obtained the best fit (Bayesian information criteria [BIC] = 3,546.95; adjusted BIC = 3,363.14; bootstrapped likelihood ratio test p < 0.0001). Differences between classes were quantitative, and groups were labeled according to severity: mild (26%), mild-moderate (28.8%), moderate (18.6%), moderate-severe (17.2%), and severe (9.3%). A significant time by class interaction was obtained (chi-square [χ²_[15]] = 30.05, p = 0.012); mild (χ²_[1] = 243.90, p < 0.05), mild-moderate (χ²_[1] = 198.03, p < 0.05), and moderate (χ²_[1] = 526.77, p < 0.05) classes displayed significantly higher treatment utilization.

Conclusion:

The classes with more symptom severity (moderate-severe and severe) displayed lower utilization of services across time when compared to participants belonging to less severe groups. However, as pairwise differences in treatment utilization between classes were not significant between every subgroup, future studies should determine whether subgroup membership predicts other treatment outcomes.

The dynamics of internalizing and externalizing comorbidity across the early school years

High rates of comorbidity are observed between internalizing and externalizing problems, yet the developmental dynamics of comorbid symptom presentations are not yet well understood. This study explored the developmental course of latent profiles of internalizing and externalizing symptoms across kindergarten, first grade, and second grade. The sample consisted of 336 children from an urban, low-income community, selected based on relatively high (61%) or low (39%) aggressive/oppositional behavior problems at school entry (64% male; 70% African American, 20% Hispanic). Teachers reported on children's symptoms in each year. An exploratory latent profile analysis of children's scores on aggression/oppositionality, hyperactivity/inattention, anxiety, and social withdrawal symptom factors revealed four latent symptom profiles: comorbid (48% of the sample in each year), internalizing (19%-23%), externalizing (21%-22%), and well-adjusted (7%-11%). The developmental course of these symptom profiles was examined using a latent transition analysis, which revealed remarkably high continuity in the comorbid symptom profile (89% from one year to the next) and moderately high continuity in both the internalizing and externalizing profiles (80% and 71%, respectively). Internalizing children had a 20% probability of remitting to the well-adjusted profile by the following year, whereas externalizing children had a 25% probability of transitioning to the comorbid profile. These results are consistent with the hypothesis that a common vulnerability factor contributes to developmentally stable internalizing-externalizing comorbidity, while also suggesting that some children with externalizing symptoms are at risk for subsequently accumulating internalizing symptoms.

Reconciling RDoC and DSM approaches in clinical psychophysiology and neuroscience

The Research Domain Criteria (RDoC) initiative endeavors to foster a science of psychopathology based around dimensions of brain-behavior relationships as opposed to subjectively based diagnostic categories. A rapidly accumulating array of transdiagnostic commonalities, across multiple objective and subjective measures, underscores the clear potential of this initiative. At the same time, a road map for guiding future RDoC research efforts is needed that draws upon the wealth of extant disorder-specific findings. In this issue, Hamm and colleagues provide an example of conceptualizing within-disorder processes in terms of dimensional brain-behavior relationships that advances the understanding of panic disorder with agoraphobia beyond the conventional nosological framework. Their findings and conceptual model are reviewed and discussed in terms of broader transdiagnostic implications.

Psychoneurometric operationalization of threat sensitivity: Relations with clinical symptom and physiological response criteria

The National Institute of Mental Health's Research Domain Criteria (RDoC) initiative calls for the incorporation of neurobiological approaches and findings into conceptions of mental health problems through a focus on biobehavioral constructs investigated across multiple domains of measurement (units of analysis). Although the constructs in the RDoC system are characterized in "process terms" (i.e., as functional concepts with brain and behavioral referents), these constructs can also be framed as dispositions (i.e., as dimensions of variation in biobehavioral functioning across individuals). Focusing on one key RDoC construct, acute threat or "fear," the current article illustrates a construct-oriented psychoneurometric strategy for operationalizing this construct in individual difference terms-as threat sensitivity (THT+). Utilizing data from 454 adult participants, we demonstrate empirically that (a) a scale measure of THT+ designed to tap general fear/fearlessness predicts effectively to relevant clinical problems (i.e., fear disorder symptoms), (b) this scale measure shows reliable associations with physiological indices of acute reactivity to aversive visual stimuli, and (c) a cross-domain factor reflecting the intersection of scale and physiological indicators of THT+ predicts effectively to both clinical and neurophysiological criterion measures. Results illustrate how the psychoneurometric approach can be used to create a dimensional index of a biobehavioral trait construct, in this case THT+, which can serve as a bridge between phenomena in domains of psychopathology and neurobiology. Implications and future directions are discussed with reference to the RDoC initiative and existing report-based conceptions of psychological traits.

Factors of psychological distress: clinical value, measurement substance, and methodological artefacts

PURPOSE

Psychometric models and statistical techniques are cornerstones of research into latent structures of specific psychopathology and general mental health. We discuss "pivot points" for future research efforts from a psychometric epidemiology perspective, emphasising sampling and selection processes of both indicators that guide data collection as well as samples that are confronted with them.

METHOD

First, we discuss how a theoretical model of psychopathology determines which empirical indicators (questions, diagnoses, etc.) and modelling methods are appropriate to test its implications. Second, we deal with how different research designs introduce different (co-)variances between indicators, potentially leading to a different understanding of latent structures. Third, we discuss widening the range of statistical models available within the "psychometrics class": the inclusion of categorical approaches can help to enlighten the debate on the structure of psychopathology and agreement on a minimal set of models might lead to greater convergence between studies. Fourth, we deal with aspects of methodology that introduce spurious (co-)variance in latent structure analysis (response styles, clustered data) and differential item functioning to gather more detailed information and to guard against over-generalisation of results, which renders assessments unfair.

CONCLUSIONS

Building on established insights, future research efforts should be more explicit about their theoretical understanding of psychopathology and how the analysis of a given indicator-respondent set informs this theoretical model. A coherent treatment of theoretical assumptions, indicators, and samples holds the key to building a comprehensive account of the latent structures of different types of psychopathology and mental health in general.

Disorders without borders: current and future directions in the meta-structure of mental disorders

PURPOSE

Classification is the cornerstone of clinical diagnostic practice and research. However, the extant psychiatric classification systems are not well supported by research evidence. In particular, extensive comorbidity among putatively distinct disorders flags an urgent need for fundamental changes in how we conceptualize psychopathology. Over the past decade, research has coalesced on an empirically based model that suggests many common mental disorders are structured according to two correlated latent dimensions: internalizing and externalizing.

METHODS

We review and discuss the development of a dimensional-spectrum model which organizes mental disorders in an empirically based manner. We also touch upon changes in the DSM-5 and put forward recommendations for future research endeavors.

RESULTS

Our review highlights substantial empirical support for the empirically based internalizing-externalizing model of psychopathology, which provides a parsimonious means of addressing comorbidity.

CONCLUSIONS

As future research goals, we suggest that the field would benefit from: expanding the meta-structure of psychopathology to include additional disorders, development of empirically based thresholds, inclusion of a developmental perspective, and intertwining genomic and neuroscience dimensions with the empirical structure of psychopathology.

Neurobehavioral Traits as Transdiagnostic Predictors of Clinical Problems

The National Institute of Mental Health Research Domain Criteria initiative (Insel et al., 2010) calls for a focus on biologically meaningful dimensional constructs in the study of clinical problems. Examples are needed of how Research Domain Criteria constructs can be linked to clinical problems. We examined how two such constructs, threat sensitivity (THT+) and weak inhibitory control (INH-), operationalized using scale measures of fear/fearlessness and inhibition/disinhibition dimensions from established structural models, predicted symptoms of multiple Diagnostic and Statistical Manual of Mental Disorders (4th edition) clinical disorders in 471 community adults. Robust relationships with internalizing disorder symptoms were evident for both trait variables, with THT+ more predictive of fear disorder symptoms and INH- more predictive of distress disorder symptoms. For substance-related problems, prediction was evident only for INH-. Additionally, interactive effects of THT+ and INH- were found for distress disorders, and to a lesser extent, fear disorders. Given their well-established physiological correlates, these dispositional variables represent prime targets for combined psychometric-neurophysiological assessment of broad liabilities to multiple forms of psychopathology.

Transdiagnostic factors of psychopathology and substance use disorders: a review

PURPOSE

Research on the structure of mental disorders and comorbidity indicates that many forms of psychopathology and substance use disorders are manifestations of relatively few transdiagnostic latent factors. These factors have important consequences for mental disorder research and applied practice.

METHODS

We provide an overview of the transdiagnostic factor literature, with particular focus on recent advances.

RESULTS

Internalizing and externalizing transdiagnostic factors have been well characterized in terms of their structures, links with disorders, stability, and statistical properties (e.g., invariance and distributions). Research on additional transdiagnostic factors, such as thought disorder, is quickly advancing latent structural models, as are integrations of transdiagnostic constructs with personality traits. Genetically informed analyses continue to clarify the origins of transdiagnostic factor levels, and links between these factors and important environmental exposures provide promising new avenues of inquiry.

CONCLUSIONS

Transdiagnostic factors account for the development and continuity of disorders and comorbidity over time, function as the primary links between disorders and important outcomes such as suicide, mediate associations between environmental exposures and disorders, provide an empirically supported classification system, and serve as foci for efficient, broadband intervention approaches. Overall, transdiagnostic factor research indicates the paramount importance of understanding these constructs and, thereby, broadening our understanding of mental disorder in general.

An examination of generalized anxiety disorder and dysthymic disorder by latent class analysis

BACKGROUND

The nosological status of generalized anxiety disorder (GAD) versus dysthymic disorder (DD) has been questioned. The aim of this study was to examine qualitative differences within (co-morbid) GAD and DD symptomatology.

METHOD

Latent class analysis was applied to anxious and depressive symptomatology of respondents from three population-based studies (2007 Australian National Survey of Mental Health and Wellbeing; National Comorbidity Survey Replication; and Netherlands Mental Health Survey and Incidence Study-2; together known as the Triple study) and respondents from a multi-site naturalistic cohort [Netherlands Study of Depression and Anxiety (NESDA)]. Sociodemographics and clinical characteristics of each class were examined.

RESULTS

A three-class (Triple study) and two-class (NESDA) model best fitted the data, reflecting mainly different levels of severity of symptoms. In the Triple study, no division into a predominantly GAD or DD co-morbidity subtype emerged. Likewise, in spite of the presence of pure GAD and DD cases in the NESDA sample, latent class analysis did not identify specific anxiety or depressive profiles in the NESDA study. Next, sociodemographics and clinical characteristics of each class were examined. Classes only differed in levels of severity.

CONCLUSIONS

The absence of qualitative differences in anxious or depressive symptomatology in empirically derived classes questions the differentiation between GAD and DD.

Psychiatric comorbidity and perceived alcohol stigma in a nationally representative sample of individuals with DSM-5 alcohol use disorder

BACKGROUND

Alcohol use disorder (AUD) is among the most stigmatized health conditions and is frequently comorbid with mood, anxiety, and drug use disorders. Theoretical frameworks have conceptualized stigma-related stress as a predictor of psychiatric disorders. We described profiles of psychiatric comorbidity among people with AUD and compared levels of perceived alcohol stigma across profiles.

METHODS

Cross-sectional data were analyzed from a general population sample of U.S. adults with past-year DSM-5 AUD (n = 3,368) from the National Epidemiologic Survey on Alcohol and Related Conditions, which was collected from 2001 to 2005. Empirically derived psychiatric comorbidity profiles were established with latent class analysis, and mean levels of perceived alcohol stigma were compared across the latent classes while adjusting for sociodemographic characteristics and AUD severity.

RESULTS

Four classes of psychiatric comorbidity emerged within this AUD sample, including those with: (i) high comorbidity, reflecting internalizing (i.e., mood and anxiety disorders) and externalizing (i.e., antisocial personality and drug use disorders) disorders; (ii) externalizing comorbidity; (iii) internalizing comorbidity; and (iv) no comorbidity. Perceived alcohol stigma was significantly higher in those with internalizing comorbidity (but not those with high comorbidity) as compared to those with no comorbidity or externalizing comorbidity.

CONCLUSIONS

Perceived stigma, as manifested by anticipations of social rejection and discrimination, may increase risk of internalizing psychiatric comorbidity. Alternatively, internalizing psychiatric comorbidity could sensitize affected individuals to perceive more negative attitudes toward them. Future research is needed to understand causal and bidirectional associations between alcohol stigma and psychiatric comorbidity.

Understanding the evolution of multimorbidity: evidences from the North West Adelaide Health Longitudinal Study (NWAHS)

OBJECTIVE

The aim of this study is to describe the evolution of multimorbidity.

STUDY DESIGN AND SETTING

Data from 1854 South Australians who participated in the North West Adelaide longitudinal Health Study (NWAHS) was collected between baseline (2000-2002) and follow-up (2008-2010). Status for eight chronic diseases (CDs) was determined by biomedical measurement or self-report. Chronic disease (CD) mean age of occurrence and order of appearance was investigated.

RESULTS

The prevalence of multimorbidity increased from 32% to 64% during the 7.8±1.1 years of follow-up. The estimated mean age of onset of a new CD was significantly older for hypertension, cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD) and younger for hypercholesterolemia, asthma and other mental problem. Hypercholesterolemia was more likely to develop as a first than as a subsequent CD (39%vs.16%, p<0.0001) while CVD (1%vs.5%, p<0.0001), diabetes (5%vs.11%, p<0.001) and COPD (6%vs.16%, p<0.0001) were less likely. The presence of mood disorders at baseline was associated with an increased risk of developing other mental disorders (36%vs.12%, p<0.0001), diabetes (18%vs.9%, p<0.01) and asthma (30%vs.21%, p<0.05).

CONCLUSION

Longitudinal data could be used to study the evolution of multimorbidity and could provide information on CDs mean age of occurrence, order of appearance and impact on the development of future CDs.

Understanding heterogeneity in PTSD: fear, dysphoria, and distress

Fear, dysphoria, and distress are prominent components in the conceptualization of posttraumatic stress disorder (PTSD). However, because our diagnostic categories are open concepts, relying on observed patterns of symptoms for classification, it is unclear whether these components represent core or auxiliary features of the disorder. Convergence across multiple indices is critical for this understanding. In this paper, we examine these components of PTSD across observed symptom patterns, broader theoretical conceptualizations, underlying information processing mechanisms of attention and memory, and underlying learning and neurobiological mechanisms. For each, evidence for similarity or distinctiveness of PTSD with other anxiety disorders and depression is examined. Throughout the review, key points of similarity to the anxiety disorders and divergence with depression argue for a distinction between core fear symptoms and auxiliary dysphoria and distress symptoms. Implications are discussed, noting that, as heterogeneity increases, core characteristics will become more diffused and ancillary constructs will gain an inflated degree of importance.

Parent, sibling and peer associations with subtypes of psychiatric and substance use disorder comorbidity in offspring

BACKGROUND

Parental substance use disorder (SUD) is associated with a range of negative offspring outcomes and psychopathology, but the clustering of these outcomes into subtypes has seldom been examined, nor have the familial and environmental contexts of these subtypes been reported. The present study examines the clustering of offspring lifetime substance use and psychiatric disorders into subtypes and characterizes them in terms of familial and non-familial influences using an offspring-of-twins design.

METHOD

Telephone-administered diagnostic interviews were used to collect data on psychiatric disorders and SUD from 488 twin fathers, 420 biological mothers and 831 offspring. Latent class analysis (LCA) was used to derive subtypes of lifetime comorbidity in offspring. Familial risk and environmental variables associated with each subtype (i.e., parenting, childhood physical or sexual abuse, perceived sibling and peer substance use) were identified using multinomial logistic regression.

RESULTS

Four classes identified by LCA were characterized as (1) unaffected, (2) alcohol abuse/dependence, (3) alcohol abuse/dependence comorbid with anxiety and depression, and (4) alcohol, cannabis abuse/dependence and nicotine dependence comorbid with conduct disorder. Inconsistent parenting, childhood physical/sexual abuse, and perceived sibling and peer substance use were significantly associated with profiles of offspring comorbidity after adjusting for familial vulnerability. Some associations were specific (i.e., perceived peer alcohol use to the AUD class), while others were general (peer smoking to all 3 comorbidity classes).

CONCLUSIONS

We observed distinct subtypes of psychiatric and SUD comorbidity in adolescents and young adults. Subtypes of offspring psychopathology have varied associations with parental psychopathology, family environment, and sibling and peer behaviors.

The structure and predictive validity of the internalizing disorders

Multivariate comorbidity research indicates mood and anxiety (internalizing) disorders share one or more common liabilities, but categorical, dimensional, and hybrid accounts of these liabilities have not been directly compared. We modeled seven internalizing disorders in a nationally representative sample of 43,093 individuals via confirmatory factor, latent class, exploratory factor mixture, and exploratory structural equation modeling analyses. A two-dimensional (distress-fear) liability structure fit best and replicated across gender, assessment waves, and lifetime/12-month diagnoses. These liabilities, not disorder-specific variation, predicted future internalizing pathology, suicide attempts, angina, and ulcer.