Diagnosis and classification of psychopathology: challenges to the current system and future directions

Toward the future of psychiatric diagnosis: the seven pillars of RDoC

BACKGROUND

Current diagnostic systems for mental disorders rely upon presenting signs and symptoms, with the result that current definitions do not adequately reflect relevant neurobiological and behavioral systems--impeding not only research on etiology and pathophysiology but also the development of new treatments.

DISCUSSION

The National Institute of Mental Health began the Research Domain Criteria (RDoC) project in 2009 to develop a research classification system for mental disorders based upon dimensions of neurobiology and observable behavior. RDoC supports research to explicate fundamental biobehavioral dimensions that cut across current heterogeneous disorder categories. We summarize the rationale, status and long-term goals of RDoC, outline challenges in developing a research classification system (such as construct validity and a suitable process for updating the framework) and discuss seven distinct differences in conception and emphasis from current psychiatric nosologies.

SUMMARY

Future diagnostic systems cannot reflect ongoing advances in genetics, neuroscience and cognitive science until a literature organized around these disciplines is available to inform the revision efforts. The goal of the RDoC project is to provide a framework for research to transform the approach to the nosology of mental disorders.

Heterogeneity of interpersonal problems among depressed young adults: associations with substance abuse and pathological personality traits

This study extended previous theory and research on interpersonal heterogeneity in depression by identifying groups of depressed young adults who differ in their type and degree of interpersonal problems, and by examining patterns of pathological personality traits and alcohol abuse among these groups. We examined the interpersonal problems, personality traits, and alcohol-related problems of 172 college students with at least moderate levels of self-reported depression on the Patient Health Questionnaire (Spitzer, Kroenke, & Williams, 1999). Scores from the Inventory of Interpersonal Problems-Short Circumplex (Soldz, Budman, Demby, & Merry, 1995) were subjected to latent profile analysis, which classified individuals into 5 distinct groups defined by the types of interpersonal problems they experience (dominant, warm, submissive, cold, and undifferentiated). As hypothesized, groups did not differ in depression severity, but did show predicted patterns of differences on normative and maladaptive personality traits, as well as alcohol-related problems. The presence of clinically meaningful interpersonal heterogeneity in depression could have important implications for designing more individualized treatments and prevention efforts for depression that target diverse associated interpersonal problems.

The structure of common mental disorders in incarcerated offenders

BACKGROUND

Dimensional models of mental disorders in community-based epidemiological samples have consistently demonstrated correlated externalizing and internalizing factors underlying common mood, anxiety, and substance use disorders. However, such analyses tend to exclude populations such as prisoners and psychiatric inpatients. As these samples have been shown to have a much higher prevalence of mental disorders and comorbidity than community samples, whether the internalizing-externalizing structure of psychopathology will replicate in such samples is unknown.

OBJECTIVES

The current study examined the consistency of this structure in a representative sample of 1837 prisoners through structural equation modeling of 10 common mental disorders along with a record-based index of antisocial behavior.

METHOD

Diagnoses were determined by administration of the Composite International Diagnostic Interview 2.1. Data were analyzed via tetrachoric correlations using the weighted least squares estimator in exploratory and confirmatory factor analyses.

RESULTS

Results revealed that a two-factor solution, entailing correlated internalizing and externalizing factors, displayed the best fit to the data.

CONCLUSIONS

This study provides additional support for characterizing common psychopathology in terms of internalizing and externalizing factors.

Mapping common psychiatric disorders: structure and predictive validity in the national epidemiologic survey on alcohol and related conditions

CONTEXT Clinical experience and factor analytic studies suggest that some psychiatric disorders may be more closely related to one another, as indicated by the frequency of their co-occurrence, which may have etiologic and treatment implications. OBJECTIVE To construct a virtual space of common psychiatric disorders, spanned by factors reflecting major psychopathologic dimensions, and locate psychiatric disorders in that space, as well as to examine whether the location of disorders at baseline predicts the prevalence and incidence of disorders at 3-year follow-up. DESIGN, SETTING, AND PATIENTS A total of 34 653 individuals participated in waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. MAIN OUTCOME MEASURES The distance between disorders at wave 1, calculated using the loadings of the factors spanning the space of disorders as coordinates. This distance was correlated with the adjusted odds ratios for age, sex, and race/ethnicity of the prevalence and incidence of Axis I disorders in wave 2, with the aim of determining whether smaller distances between disorders at wave 1 predicts higher disorder prevalence and incidence at wave 2. RESULTS A model with 3 correlated factors provided an excellent fit (Comparative Fit Index = 0.99, Tucker-Lewis Index = 0.98, root mean square error of approximation = 0.008) for the structure of common psychiatric disorders and was used to span the space of disorders. Distances ranged from 0.070 (between drug abuse and alcohol dependence) to 1.032 (between drug abuse and dysthymia). The correlation of distance between disorders in wave 1 with adjusted odds ratios of prevalence in wave 2 was -0.56. The correlation of distance in wave 1 with adjusted odds ratios of incidence in wave 2 was -0.57. CONCLUSIONS Mapping psychiatric disorders can be used to quantify the distances among disorders. Proximity in turn can be used to predict prospectively the incidence and prevalence of Axis I disorders.

Are sexual problems a form of internalizing psychopathology? A structural equation modeling analysis

Sexual dysfunctions, depression, and anxiety disorders have high rates of comorbidity. The aim of this study was to empirically evaluate an expanded model of internalizing psychopathology (Krueger, 1999) that includes sexual problems, based on these patterns of comorbidity. Responses to an online survey from a sexually active community sample (n = 563) were analyzed using structural equation modeling to compare the fit of four alternative models for males and females. An expanded model of the internalizing spectrum that included sexual problems was a good fit for the pattern of interrelationships in the female data. However, the weak relationships between the observed variables in the male data meant that none of the models provided an adequate fit for men. This study offers preliminary evidence for the utility of a model of the internalizing spectrum that includes sexual problems for women, which could facilitate a better understanding of the role of common underlying psychopathological processes between disorders and offer a first step towards effective diagnosis and treatment. Future research should focus on clinical and representative samples, using other measurement methods.

Etiological distinctions between aggressive and non-aggressive antisocial behavior: results from a nuclear twin family model

A recent meta-analysis of 103 studies Burt (Clinical Psychology Review, 29:163-178, 2009a) highlighted the presence of etiological distinctions between aggressive (AGG) and non-aggressive rule-breaking (RB) dimensions of antisocial behavior, such that AGG was more heritable than was RB, whereas RB was more influenced by the shared environment. Unfortunately, behavioral genetic research on antisocial behavior to date (and thus, the research upon which the meta-analysis was based) has relied almost exclusively on the classical twin model. This reliance is problematic, as the strict assumptions that undergird this model (e.g., shared environmental and dominant genetic influences are not present simultaneously; there is no assortative mating) can have significant consequences on heritability estimates when they are violated. The nuclear twin family model, by contrast, allows researchers to relax and statistically evaluate many of the assumptions of the classical twin design by incorporating parental self-report data along with the more standard twin data. The goal of the current study was thus to evaluate whether prior findings of etiological distinctions between AGG and RB persisted when using the nuclear twin family model. We examined a sample of 312 child twin families from the Michigan State University Twin Registry. Results strongly supported prior findings of etiological distinctions between AGG and RB, such that broad genetic influences were observed to be particularly important to AGG whereas shared environmental influences contributed only to RB. Nevertheless, the current findings also implied that additive genetic influences on antisocial behavior may be overestimated when using the classical twin design.

How research on the meta-structure of psychopathology aids in understanding biological correlates of mood and anxiety disorders

Research on biological correlates of psychopathology stands to benefit from being interwoven with an empirically based, quantitative model of mental disorders. Empirically-based classification approaches help to deal effectively with issues such as comorbidity among diagnoses, which often serve as challenges to interpreting research on biological correlates. With regard to the mood and anxiety disorders specifically, quantitative research shows how mood and anxiety disorders are well conceptualized as elements within a broad internalizing spectrum of psychopathology, such that many putative biological correlates of specific disorders may be better conceptualized as delineating the pathophysiology of the broader mechanisms underlying multiple disorders.

Expanding stress generation theory: test of a transdiagnostic model

Originally formulated to understand the recurrence of depressive disorders, the stress generation hypothesis has recently been applied in research on anxiety and externalizing disorders. Results from these investigations, in combination with findings of extensive comorbidity between depression and other mental disorders, suggest the need for an expansion of stress generation models to include the stress generating effects of transdiagnostic pathology as well as those of specific syndromes. Employing latent variable modeling techniques to parse the general and specific elements of commonly co-occurring Axis I syndromes, the current study examined the associations of transdiagnostic internalizing and externalizing dimensions with stressful life events over time. Analyses revealed that, after adjusting for the covariation between the dimensions, internalizing was a significant predictor of interpersonal dependent stress, whereas externalizing was a significant predictor of noninterpersonal dependent stress. Neither latent dimension was associated with the occurrence of independent, or fateful, stressful life events. At the syndrome level, once variance due to the internalizing factor was partialed out, unipolar depression contributed incrementally to the generation of interpersonal dependent stress. In contrast, the presence of panic disorder produced a "stress inhibition" effect, predicting reduced exposure to interpersonal dependent stress. Additionally, dysthymia was associated with an excess of noninterpersonal dependent stress. The latent variable modeling framework used here is discussed in terms of its potential as an integrative model for stress generation research.

Annual research review: categories versus dimensions in the classification and conceptualisation of child and adolescent mental disorders--implications of recent empirical study

The question of whether child and adolescent mental disorders are best classified using dimensional or categorical approaches is a contentious one that has equally profound implications for clinical practice and scientific enquiry. Here, we explore this issue in the context of the forth coming publication of the DSM-5 and ICD-11 approaches to classification and diagnosis and in the light of recent empirical studies. First, we provide an overview of current category-based systems and dimensional alternatives. Second, we distinguish the various strands of meaning and levels of analysis implied when we talk about categories and dimensions of mental disorder--distinguishing practical clinical necessity, formal diagnostic systems, meta-theoretical beliefs and empirical reality. Third, we introduce the different statistical techniques developed to identify disorder dimensions and categories in childhood populations and to test between categorical and dimensional models. Fourth, we summarise the empirical evidence from recent taxometric studies in favour of the 'taxonomic hypothesis' that mental disorder categories reflect discrete entities with putative specific causes. Finally, we explore the implications of these findings for clinical practice and science.

The structure of Diagnostic and Statistical Manual of Mental Disorders (4th edition, text revision) personality disorder symptoms in a large national sample

We examined the latent structure underlying the criteria for DSM-IV-TR (American Psychiatric Association, 2000, Diagnostic and statistical manual of mental disorders (4th ed., text revision). Washington, DC: Author.) personality disorders in a large nationally representative sample of U.S. adults. Personality disorder symptom data were collected using a structured diagnostic interview from approximately 35,000 adults assessed over two waves of data collection in the National Epidemiologic Survey on Alcohol and Related Conditions. Our analyses suggested that a seven-factor solution provided the best fit for the data, and these factors were marked primarily by one or at most two personality disorder criteria sets. A series of regression analyses that used external validators tapping Axis I psychopathology, treatment for mental health problems, functioning scores, interpersonal conflict, and suicidal ideation and behavior provided support for the seven-factor solution. We discuss these findings in the context of previous studies that have examined the structure underlying the personality disorder criteria as well as the current proposals for DSM-5 personality disorders.

DSM-Oriented Scales of the Child Behavior Checklist and Youth Self-Report in clinically referred Spanish children

The Achenbach System of Empirically Based Assessment (ASEBA) is an example of the efforts to integrate categorical and dimensional assessment methods. The latest editions of the Child Behavior Checklist (CBCL) and the Youth Self-Report (YSR) included the DSM-Oriented Scales, constructed in rational manner based on the items making up these inventories.

OBJECTIVE

To analyze the psychometric properties of the DSM-Oriented Scales of the CBCL and YSR.

METHOD

A clinical sample of 420 children and adolescents (aged 8-17 years) was assessed with the CBCL and YSR, with a structured diagnostic interview and with measures of functional impairment to study the reliability and validity of the DSM-Oriented Scales.

RESULTS

Internal consistency ranged from moderate to good for all the scales except the DSM-Anxiety Problems Scale. Agreement between parents and children ranged between moderate and low values. Kappa coefficients showed moderate agreement in the different symptoms. The DSM-Oriented Scales presented acceptable diagnostic power for DSM-IV disorders and a significant relationship with measures of functional impairment.

CONCLUSION

The DSM-Oriented Scales constitute a useful approach from the dimensional model to the DSM-IV disorders in Spanish clinical population.

Multivariate analysis of anxiety disorders yields further evidence of linkage to chromosomes 4q21 and 7p in panic disorder families

Replication has been difficult to achieve in linkage studies of psychiatric disease. Linkage studies of panic disorder have indicated regions of interest on chromosomes 1q, 2p, 2q, 3, 7, 9, 11, 12q13, 12q23, and 15. Few regions have been implicated in more than one study. We examine two samples, the Iowa (IA) and the Columba panic disorder families. We use the fuzzy-clustering method presented by Kaabi et al. [Kaabi et al. (2006); Am J Hum Genet 78: 543-553] to summarize liability to panic disorder, agoraphobia, simple phobia, and social phobia. Kaabi et al. applied this method to the Yale panic disorder linkage families and found evidence of linkage to chromosomes 4q21, 4q32, 7p, and 8. When we apply the same method to the IA families, we obtain overlapping evidence of linkage to chromosomes 4q21 and 7p. Additionally, we find evidence of linkage on chromosomes 1, 5, 6, 16, and 22. The Columbia (CO) data does not indicate linkage to any of the Kaabi et al. peaks, instead implicating chromosomes 2 and 22q11 (2 Mb from COMT). There is some evidence of overlapping linkage between the IA and CO datasets on chromosomes 1 and 14. While use of fuzzy clustering has not produced complete concordance across datasets, it has produced more than previously seen in analyses of panic disorder proper. We conclude that chromosomes 4q21 and 7p should be considered strong candidate regions for panic and fear-associated anxiety disorder loci. More generally, this suggests that analyses including multiple aspects of psychopathology may lead to greater consistency across datasets.

The utility of the Kessler Screening Scale for Psychological Distress (K6) in two American Indian communities

The Kessler Screening Scale for Psychological Distress (K6; Kessler et al., 2002) has been used widely as a screener for mental health problems and as a measure of severity of impact of mental health problems. However, the applicability and utility of this measure for assessments within American Indian communities has not been explored. Data were drawn from a large-scale epidemiological study conducted in cooperation with 2 American Indian populations. Participants (N = 3,084) were 15-54 years of age and living on or near their home reservations; each completed an interview that included a version of the Composite International Diagnostic Interview (Robins, Wing, Wittchen, & Helzer, 1988) and the K6. A measure of both physical- and mental-health-related quality of life-the Medical Outcome Study's Short Form-36 (Ware & Sherbourne, 1992)-was used to examine the importance of the K6 over and above psychiatric diagnoses. The K6 was shown to be an appropriate screening and severity measure for mood disorders in these 2 samples. It also predicted health-related quality of life over and above that predicted by diagnoses alone. Inclusion of a measure such as the K6 as a complement to more traditional dichotomous diagnoses in both research and clinical practice is recommended.

Computerized adaptive assessment of personality disorder: introducing the CAT-PD project

Assessment of personality disorders (PD) has been hindered by reliance on the problematic categorical model embodied in the most recent Diagnostic and Statistical Model of Mental Disorders (DSM), lack of consensus among alternative dimensional models, and inefficient measurement methods. This article describes the rationale for and early results from a multiyear study funded by the National Institute of Mental Health that was designed to develop an integrative and comprehensive model and efficient measure of PD trait dimensions. To accomplish these goals, we are in the midst of a 5-phase project to develop and validate the model and measure. The results of Phase 1 of the project--which was focused on developing the PD traits to be assessed and the initial item pool--resulted in a candidate list of 59 PD traits and an initial item pool of 2,589 items. Data collection and structural analyses in community and patient samples will inform the ultimate structure of the measure, and computerized adaptive testing will permit efficient measurement of the resultant traits. The resultant Computerized Adaptive Test of Personality Disorder (CAT-PD) will be well positioned as a measure of the proposed DSM-5 PD traits. Implications for both applied and basic personality research are discussed.

Self-discrepancies in bipolar disorder: Comparison of manic, depressed, remitted and normal participants

OBJECTIVES

To study the role of self-discrepancies in different phases of bipolar disorder (manic-depression).

METHOD AND DESIGN

Patients with a diagnosis of bipolar disorder in three groups, currently depressed, currently manic or hypomanic, and currently in remission, together with healthy control participants, were administered a modified version of Higgins' Selves Questionnaire. Consistencies between the self-actual, self-ideal and self-ought representations were calculated, together with consistencies between the self-actual representation and the believed views of generalized others about the self.

RESULTS

In contrast to all other groups, bipolar depressed patients showed marked discrepancies between their self-actual and self-ideal representations, and between their self-actual and self-ought representations. Manic or hypomanic patients showed higher self-actual:self-ideal consistency than non-patient controls. The differences between the depressed participants and the other groups appeared to be accounted for by their very negative self-actual descriptions. Participants in all four groups showed high levels of consistency between self-perceptions and the believed perceptions of others about the self.

CONCLUSIONS

These findings confirm that beliefs about the self differ between different phases of bipolar disorder and are consistent with the hypothesis that the manic phase involves active avoidance of discrepancies between the self and self-ideals.

Paranoia and emotion perception across the continuum

OBJECTIVES

Persons with high levels of paranoid ideation may be more sensitive to emotional stimuli, particularly negative emotions, reflecting the operation of a paranoid schema. However, this finding has not been consistently supported and needs further study. This study examined the effect of paranoia, as measured on a continuum, on emotion perception. It was predicted that higher levels of paranoia would be associated with improved emotion perception scores with better recognition for negative emotions than positive.

DESIGN

A four-group ANOVA design was used to compare participants with clinical and sub-clinical paranoia to reflect the continuum view of paranoia.

METHODS

A group with persecutory delusions (N=30) was compared with three sub-clinical groups (N=88) on two posed emotion perception tasks. The sub-clinical participants were divided into high, moderate, and low groups based on scores from the Paranoia Scale, a widely used measure of sub-clinical paranoia.

RESULTS

Persons with persecutory delusions had lower overall emotion perception scores than all of the sub-clinical groups. For negative emotions, persons with persecutory delusions had lower identification scores than the moderate and low sub-clinical groups, but were no different than the high sub-clinical group. Anger was especially problematic for clinical participants. There were no differences for positive emotions.

CONCLUSIONS

Instead of an enhanced sensitivity for the recognition of emotional states, higher levels of paranoia were linked to a performance deficit on emotion perception tasks. The deficits in emotion perception may reflect the increased skepticism and scrutiny associated with posed emotion tasks (Davis & Gibson, 2000). Research should begin to focus on the underlying mechanisms of emotion perception deficits in paranoia.

Anxiety as a context for understanding associations between hypochondriasis, obsessive-compulsive, and panic attack symptoms

In the context of the integrative model of anxiety and depression, we examined whether the essential problem of hypochondriasis is one of anxiety. When analyzed, data from a large nonclinical sample corresponded to the integrative model's characterization of anxiety as composed of both broad, shared and specific, unique symptom factors. The unique hypochondriasis, obsessive-compulsive, and panic attack symptom factors all had correlational patterns expected of anxiety with the shared, broad factors of negative emotionality and positive emotionality. A confirmatory factor analysis showed a higher-order, bifactor model was the best fit to our data; the shared and the unique hypochondriasis and anxiety symptom factors both contributed substantial variance. This study provides refinements to an empirically based taxonomy and clarifies what hypochondriasis is and, importantly, what it is not.

A taxometric study of hypochondriasis symptoms

Hypochondriasis has been conceptualized as both a distinct category that is characterized by a disabling illness preoccupation and as a continuum of health concerns. Empirical support for one of these theoretical models will clarify inconsistent assessment approaches and study designs that have impeded theory and research. To facilitate progress, taxometric analyses were conducted to determine whether hypochondriasis is best understood as a discrete category, consistent with the DSM, or as a dimensional entity, consistent with prevailing opinion and most self-report measures. Data from a large undergraduate sample that completed 3 hypochondriasis symptom measures were factor analyzed. The 4 factor analytically derived symptom indicators were then used in these taxometric analyses. Consistent with our hypotheses and existing theory, results supported a dimensional structure for hypochondriasis. Implications for the conceptualization of hypochondriasis and directions for future study are discussed.

Paradigm shifts and the development of the diagnostic and statistical manual of mental disorders: past experiences and future aspirations

OBJECTIVE

Work is currently under way on the Diagnostic and Statistical Manual of Mental Disorders (DSM), Fifth Edition, due to be published by the American Psychiatric Association in 2013. Dissatisfaction with the current categorical descriptive approach has led to aspirations for a paradigm shift for DSM-5.

METHOD

A historical review of past revisions of the DSM was performed. Efforts undertaken before the start of the DSM-5 development process to conduct a state-of-the science review and set a research agenda were examined to determine if results supported a paradigm shift for DSM-5. Proposals to supplement DSM-5 categorical diagnosis with dimensional assessments are reviewed and critiqued.

RESULTS

DSM revisions have alternated between paradigm shifts (the first edition of the DSM in 1952 and DSM-III in 1980) and incremental improvements (DSM-II in 1968, DSM-III-R in 1987, and DSM-IV in 1994). The results of the review of the DSM-5 research planning initiatives suggest that despite the scientific advances that have occurred since the descriptive approach was first introduced in 1980, the field lacks a sufficiently deep understanding of mental disorders to justify abandoning the descriptive approach in favour of a more etiologically based alternative. Proposals to add severity and cross-cutting dimensions throughout DSM-5 are neither paradigm shifting, given that simpler versions of such dimensions are already a component of DSM-IV, nor likely to be used by busy clinicians without evidence that they improve clinical outcomes.

CONCLUSIONS

Despite initial aspirations that DSM would undergo a paradigm shift with this revision, DSM-5 will continue to adopt a descriptive categorical approach, albeit with a greatly expanded dimensional component.

Social phobia: further evidence of dimensional structure

OBJECTIVE

Social phobia is a common mental disorder associated with significant impairment. Current research and treatment models of social phobia rely on categorical diagnostic conceptualizations lacking empirical support. This study aims to further research exploring whether social phobia is best conceptualized as a dimension or a discrete categorical disorder.

METHODS

This study used three distinct taxometric techniques (mean above minus below a cut, maximum Eigen value and latent mode) to explore the latent structure of social phobia in two large epidemiological samples, using indicators derived from diagnostic criteria and associated avoidant personality traits.

RESULTS

Overall, outcomes from multiple taxometric analyses supported dimensional structure. This is consistent with conceptualizations of social phobia as lying on a continuum with avoidant personality traits.

CONCLUSIONS

Support for the dimensionality of social phobia has important implications for future research, assessment, treatment, and public policy.

Comorbidity: a network perspective

The pivotal problem of comorbidity research lies in the psychometric foundation it rests on, that is, latent variable theory, in which a mental disorder is viewed as a latent variable that causes a constellation of symptoms. From this perspective, comorbidity is a (bi)directional relationship between multiple latent variables. We argue that such a latent variable perspective encounters serious problems in the study of comorbidity, and offer a radically different conceptualization in terms of a network approach, where comorbidity is hypothesized to arise from direct relations between symptoms of multiple disorders. We propose a method to visualize comorbidity networks and, based on an empirical network for major depression and generalized anxiety, we argue that this approach generates realistic hypotheses about pathways to comorbidity, overlapping symptoms, and diagnostic boundaries, that are not naturally accommodated by latent variable models: Some pathways to comorbidity through the symptom space are more likely than others; those pathways generally have the same direction (i.e., from symptoms of one disorder to symptoms of the other); overlapping symptoms play an important role in comorbidity; and boundaries between diagnostic categories are necessarily fuzzy.

The diagnosis of mental disorders: the problem of reification

A pressing need for interrater reliability in the diagnosis of mental disorders emerged during the mid-twentieth century, prompted in part by the development of diverse new treatments. The Diagnostic and Statistical Manual of Mental Disorders (DSM), third edition answered this need by introducing operationalized diagnostic criteria that were field-tested for interrater reliability. Unfortunately, the focus on reliability came at a time when the scientific understanding of mental disorders was embryonic and could not yield valid disease definitions. Based on accreting problems with the current DSM-fourth edition (DSM-IV) classification, it is apparent that validity will not be achieved simply by refining criteria for existing disorders or by the addition of new disorders. Yet DSM-IV diagnostic criteria dominate thinking about mental disorders in clinical practice, research, treatment development, and law. As a result, the modern DSM system, intended to create a shared language, also creates epistemic blinders that impede progress toward valid diagnoses. Insights that are beginning to emerge from psychology, neuroscience, and genetics suggest possible strategies for moving forward.

Intergenerational transmission of multiple problem behaviors: prospective relationships between mothers and daughters

Much of the research examining intergenerational continuity of problems from mother to offspring has focused on homotypic continuity (e.g., depression), despite the fact that different types of mental health problems tend to cluster in both adults and children. It remains unclear whether mothers with multiple mental health problems compared to mothers with fewer or no problems are more likely to have daughters with multiple mental health problems during middle childhood (ages 7 to 11). Six waves of maternal and child data from the Pittsburgh Girls Study (n = 2,451) were used to examine the specificity of effects of maternal psychopathology on child adjustment. Child multiple mental health problems comprised disruptive behavior, ADHD symptoms, depressed mood, anxiety symptoms and somatic complaints, while maternal multiple mental health problems consisted of depression, prior conduct problems and somatic complaints. Generalized Estimating Equations (GEE) was used to examine the prospective relationships between mother’s single and multiple mental health problems and their daughter’s single and multiple mental health problems across the elementary school-aged period (ages 7–11 years). The results show that multiple mental health problems in the mothers predicted multiple mental health problems in the daughters even when earlier mental health problem of the daughters, demographic factors, and childrearing practices were controlled. Maternal low parental warmth and harsh punishment independently contributed to the prediction of multiple mental health problems in their daughter, but mediation analyses showed that the contribution of parenting behaviors to the explanation of girls’ mental health problems was small.

Integrating structural and epidemiological research to inform the classification of psychopathology

Given the enormous influence of classification on the major clinical, research, and administrative activities of mental health professionals, understanding the true number and nature of disorders and the reasons for their comorbidity is an important public health priority. However, while studies of latent structure have yielded valuable information about disorder boundaries, their reliance on non-representative samples and failure to evaluate the practical implications of structural findings has limited their ability to effect nosological change. Conversely, community epidemiology studies, which inform classification by assessing the implications of diagnostic criteria in representative samples, have been limited by their focus on mental disorders as they are currently conceptualized by the field rather than on correlates and consequences of these disorders as they actually exist in nature. I consider the potential value of integrating systematically the methods of structural research with the methods of epidemiological research, exploring five ways in which these largely independent traditions may profitably be combined to inform the next classifications of mental disorders. By capitalizing on the complementary strengths of structural and epidemiological research, an integrated approach has significant potential to advance understanding of the nature of psychopathology and improve the validity and utility of its diagnosis.

Harmonisation of ICD-11 and DSM-V: opportunities and challenges

BACKGROUND

Differences in the ICD-10 and DSM-IV definitions for the same disorder impede international communication and research efforts. The forthcoming parallel development of DSM-V and ICD-11 offers an opportunity to harmonise the two classifications.

AIMS

This paper aims to facilitate the harmonisation process by identifying diagnostic differences between the two systems.

METHOD

DSM-IV-TR criteria sets and the ICD-10 Diagnostic Criteria for Research were compared and categorised into those with identical definitions, those with conceptually based differences and those in which differences are not conceptually based and appear to be unintentional.

RESULTS

Of the 176 criteria sets in both systems, only one, transient tic disorder, is identical. Twenty-one per cent had conceptually based differences and 78% had non-conceptually based differences.

CONCLUSIONS

Harmonisation of criteria sets, especially those with non-conceptually based differences, should be prioritised in the DSM-V and ICD-11 development process. Prior experience with the DSM-IV and ICD-10 harmonisation effort suggests that for the process to be successful steps should be taken as early as possible.

Aggressive versus nonaggressive antisocial behavior: distinctive etiological moderation by age

Research has supported the existence of distinct behavioral patterns, demographic correlates, and etiologic mechanisms for aggressive (AGG) versus nonaggressive but delinquent (DEL) antisocial behavior. Though behavioral genetic studies have the potential to further crystallize these dimensions, inconsistent results have limited their contribution. These inconsistencies may stem in part from the limited attention paid to the impact of age. In the current study, the authors thus examined age-related etiological moderation of AGG and DEL antisocial behavior in a sample of 720 sibling pairs (ranging in age from 10 to 18 years) with varying degrees of genetic relatedness. Results reveal that the magnitude of genetic and environmental influences on AGG remained stable across adolescence. By contrast, genetic influences on DEL increased dramatically with age, whereas shared environmental influences decreased. Subsequent longitudinal analyses fully replicated these results. Such findings highlight etiological distinctions between aggression and delinquency, and offer insights into the expression of genetic influences during development.

A taxometric study of alcohol abuse and dependence in a general population sample: evidence of dimensional latent structure and implications for DSM-V

AIMS

To explore, with the aid of taxometric analysis, whether alcohol abuse and alcohol dependence are each conceptualized most effectively as single latent dimensions or distinct latent categories.

DESIGN

Data were taken from a nationally representative cross-sectional epidemiological survey of psychiatric and substance use disorders.

SETTING

General population of Australia.

PARTICIPANTS

A subsample of all respondents who had consumed at least 12 drinks in the year prior to the survey and who had consumed at least three drinks on at least one single day (n = 4920 of a possible 10,641).

MEASUREMENTS

DSM-IV criteria for alcohol abuse and dependence were assessed with the Composite International Diagnostic Interview, version 2.1. Two independent taxometric procedures, MAXimum EIGenvalue (MAXEIG) and mean above minus below a cut (MAMBAC), together with analysis of simulated dimensional and categorical data sets, were carried out. Findings Consistent evidence was found for a single latent dimension underlying the symptoms of alcohol dependence. Less consistent evidence of dimensionality was found for the symptoms of alcohol abuse.

CONCLUSIONS

These findings support the growing consensus regarding the need for continuous measures of alcohol use disorders to complement the traditional categorical representations in upcoming versions of the major psychiatric classification systems.

A memory-based model of posttraumatic stress disorder: evaluating basic assumptions underlying the PTSD diagnosis

In the mnemonic model of posttraumatic stress disorder (PTSD), the current memory of a negative event, not the event itself, determines symptoms. The model is an alternative to the current event-based etiology of PTSD represented in the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000). The model accounts for important and reliable findings that are often inconsistent with the current diagnostic view and that have been neglected by theoretical accounts of the disorder, including the following observations. The diagnosis needs objective information about the trauma and peritraumatic emotions but uses retrospective memory reports that can have substantial biases. Negative events and emotions that do not satisfy the current diagnostic criteria for a trauma can be followed by symptoms that would otherwise qualify for PTSD. Predisposing factors that affect the current memory have large effects on symptoms. The inability-to-recall-an-important-aspect-of-the-trauma symptom does not correlate with other symptoms. Loss or enhancement of the trauma memory affects PTSD symptoms in predictable ways. Special mechanisms that apply only to traumatic memories are not needed, increasing parsimony and the knowledge that can be applied to understanding PTSD.

Revisiting the structure of mental disorders: borderline personality disorder and the internalizing/externalizing spectra

OBJECTIVE

Researchers have turned to dimensional models of psychopathology as a means of explaining robust patterns of comorbidity. A hierarchical model consisting of internalizing and externalizing dimensions has been a useful approach to understanding comorbidity among some mental disorders, although a limited number of disorders have been examined within this framework. The objective of the present study is to determine how borderline personality disorder fits into this framework.

DESIGN AND METHODS

Dimensional measures of nine psychiatric disorders were used in a confirmatory factors analysis to compare five models of comorbidity in 1,197 members (N=541 women) of a population-based sample. Symptom composites were derived from the Michigan Composite International Diagnostic Interview and the International Personality Disorders Examination Questionnaire.

RESULTS

Five models were fit to dimensional indicators of nine disorders. A model in which borderline personality disorder served as a multidimensional indicator of the externalizing factor and the anxious-misery subfactor of internalizing disorders provided the best fit to the data in the whole sample and in men. For women, this model also fit well but an alternative model in which borderline personality disorder served only as an indicator of the anxious-misery subfactor of internalizing disorders fit equally well.

CONCLUSIONS

The present study demonstrates the utility of the internalizing/externalizing framework for characterizing personality disorders as well as Axis I disorders. Future work should explore how other personality disorders fit into this framework.

Examining the validity of autism spectrum disorder subtypes

The classification of autism spectrum disorders (ASDs) is a topic of debate among clinicians and researchers with many questioning the validity of the distinction among subtypes. This manuscript examines the validity of three ASD subtypes (Autism, Asperger's, and PDDNOS) by reviewing 22 studies published between 1994 and 2006. We reviewed studies that examined differences between the subtypes in terms of clinical and demographic characteristics, neuropsychological profiles, comorbidity, and prognosis. Results largely did not support differences between autism and Asperger's disorder based on current diagnostic criteria. Overall, the most salient group differences were noted when samples were categorized on IQ. Drawing definitive conclusions is difficult due to the inconsistent application of diagnostic criteria and circularity in methods.

A brief taxometrics primer

Taxometric procedures provide an empirical means of determining which psychiatric disorders are typologically distinct from normal behavioral functioning. Although most disorders reflect extremes along continuously distributed behavioral traits, identifying those that are discrete has important implications for accurate diagnosis, effective treatment, early identification of risk, and improved understanding of etiology. This article provides (a) brief descriptions of the conceptual bases of several taxometric procedures, (b) example analyses using simulated data, and (c) strategies for avoiding common pitfalls that are often observed in taxometrics research. To date, most taxometrics studies have appeared in the adult psychopathology literature. It is hoped that this primer will encourage interested readers to extend taxometrics research to child and adolescent populations.

Critical developments in the assessment of personality disorder

BACKGROUND

The assessment of personality disorder is currently inaccurate, largely unreliable, frequently wrong and in need of improvement.

AIMS

To describe the errors inherent in the current systems and to indicate recent ways of improving personality assessment.

METHOD

Historical review, description of recent developments, including temporal stability, and of studies using document-derived assessment.

RESULTS

Studies of interrater agreement and accuracy of diagnosis in complex patients with independently established personality status using document-derived assessment (PAS-DOC) with a four personality cluster classification, showed very good agreement between raters for the flamboyant cluster B group of personalities, generally good agreement for the anxious/dependent cluster C group and inhibited (obsessional) cluster D group, but only fair agreement for the withdrawn cluster A group. Overall diagnostic accuracy was 71%.

CONCLUSIONS

Personality function or diathesis, a fluctuating state, is a better description than personality disorder. The best form of assessment is one that uses longitudinal repeated measures using a four-dimensional system.

Social isolation in prairie voles induces behaviors relevant to negative affect: toward the development of a rodent model focused on co-occurring depression and anxiety

Recent evidence suggests substantial overlap between mood and anxiety disorders, both in clinical presentation and associated features. A theoretical framework to account for this overlap focuses on negative affectivity, defined as the disposition to experience negative emotional states, including fear, sadness, and guilt. This model has been successful in explaining the co-occurrence of depressive and anxiety disorders in humans. As a next step, development of an animal model focused on both depression- and anxiety-relevant behaviors may advance understanding of depression-anxiety symptom overlap, relations of these disorders with associated medical conditions and responses to treatment. This study was designed to investigate inducible and quantifiable depression- and anxiety-like behaviors in prairie voles (Microtus ochrogaster). Adult, female prairie voles were exposed to 4 weeks of social pairing (control) or isolation, an established stressor for socially monogamous mammals (including humans). Operational measures of depression (sucrose intake and behaviors in the forced swim test), anxiety (behaviors in the elevated plus maze), and aggression (responses to an unrelated prairie vole pup) were investigated. Social isolation induced a progressive decline in sucrose intake and increased immobility time during the forced swim test. Social isolation also decreased the amount of time spent in the open arms of the elevated plus maze, and increased pup-directed attack behavior. The current findings suggest that isolation induces behaviors reflecting elevated negative affect. These results may provide a foundation for creating a rodent model to examine the mechanisms underlying comorbid mood and anxiety disorders.

Taxometric analysis: introduction and overview

OBJECTIVE

The purpose of this article is to provide an introduction to taxometric procedures, and a set of mathematical tools utilized to examine the latent structure of constructs as they occur in nature (i.e., categorical versus dimensional).

METHOD

Taxometric procedures have the potential to inform the Diagnostic and Statistical Manual of Mental Disorders (DSM) conceptualization of eating disorders, and provide unique information about the construct validity of the current diagnostic scheme. Existing empirical studies which utilize taxometric procedures are reviewed, and the current DSM diagnostic categories are evaluated in terms of how well they square with empirical findings.

CONCLUSION

Finally, the implications of the taxometrics literature for future DSM classification of eating disorders, as well as guidelines for future areas of research, are discussed.

Linking antisocial behavior, substance use, and personality: an integrative quantitative model of the adult externalizing spectrum

Antisocial behavior, substance use, and impulsive and aggressive personality traits often co-occur, forming a coherent spectrum of personality and psychopathology. In the current research, the authors developed a novel quantitative model of this spectrum. Over 3 waves of iterative data collection, 1,787 adult participants selected to represent a range across the externalizing spectrum provided extensive data about specific externalizing behaviors. Statistical methods such as item response theory and semiparametric factor analysis were used to model these data. The model and assessment instrument that emerged from the research shows how externalizing phenomena are organized hierarchically and cover a wide range of individual differences. The authors discuss the utility of this model for framing research on the correlates and the etiology of externalizing phenomena.

Reinterpreting comorbidity: a model-based approach to understanding and classifying psychopathology

Comorbidity has presented a persistent puzzle for psychopathology research. We review recent literature indicating that the puzzle of comorbidity is being solved by research fitting explicit quantitative models to data on comorbidity. We present a meta-analysis of a liability spectrum model of comorbidity, in which specific mental disorders are understood as manifestations of latent liability factors that explain comorbidity by virtue of their impact on multiple disorders. Nosological, structural, etiological, and psychological aspects of this liability spectrum approach to understanding comorbidity are discussed.

Relative reinforcing value of exercise in inpatients with anorexia nervosa: model development and pilot data

OBJECTIVE

This study sought to quantify, among patients hospitalized for the treatment of anorexia nervosa (AN), the reinforcing value of exercise, defined as the amount of work a patient would expend for the opportunity to exercise.

METHOD

Sixteen inpatients with AN performed a computerized progressive ratio (PR) task for the opportunity to exercise for either 15 or 30 min, or a monetary voucher. Exercise "breakpoint" was calculated and compared with clinical measures.

RESULTS

Patients performed an average of 1134.4 (+/-751.2) button presses for exercise. Exercise breakpoint was significantly correlated with the Beck Depression Inventory (BDI; r = .728, p = .001), and there was a trend toward a correlation with the Commitment to Exercise Scale (CES; Davis, 1993; r = .490, p = .054).

CONCLUSION

Results support the feasibility and potential utility of this novel application of the PR task to quantify the reinforcing value of exercise in AN. The association between exercise and depression is consistent with some prior studies in AN. The trend toward an association with CES scores suggests that breakpoint captures an aspect of the motivation for exercise in this population.

Evaluation of the Computerized Assessment System for Psychotherapy Evaluation and Research (CASPER) as a measure of treatment effectiveness with psychiatric inpatients

Assessment procedures to evaluate inpatient treatment effectiveness can provide information to inform clinical practice. The Computerized Assessment System for Psychotherapy Evaluation and Research (CASPER) represents a standardized approach to assess patients' target problems that combines elements of individualized and nomothetic approaches. Although previous evaluations of CASPER with other patient populations have been encouraging, its use as a measure of change with an inpatient population has not been examined. In this study, 75 psychiatric inpatients completed CASPER and the Behavior and Symptom Identification Scale-32 (BASIS-32) at hospital admission and discharge. Results supported the concurrent validity of CASPER as a measure of pre- and posttreatment functioning and suggested that CASPER may provide a sensitive measure of change during inpatient treatment. Findings also supported the notion that patients' ratings of the extent to which their treatment focused on the problems they identified as a high priority were related to their overall treatment satisfaction.