Rethinking the mood and anxiety disorders: A quantitative hierarchical model for DSM-V.

Abstract

DSM-IV (American Psychiatric Association, 1994) groups disorders into diagnostic classes based on the subjective criterion of "shared phenomenological features". We now have sufficient data to eliminate this rational system and replace it with an empiricallybased structure that reflects the actual similarities among disorders. The existing structural evidence establishes that the mood and anxiety disorders should be collapsed together in an overarching class of emotional disorders, which can be decomposed into three subclasses: the bipolar disorders (bipolar I, bipolar II, cyclothymia), the distress disorders (major depression, dysthymic disorder, generalized anxiety disorder, posttraumatic stress disorder) and the fear disorders (panic disorder, agoraphobia, social phobia, specific phobia). The optimal placement of other syndromes (e.g., obsessivecompulsive disorder) needs to be clarified in future research.Rethinking the mood and anxiety disorders 4 Rethinking the Mood and Anxiety Disorders: A Quantitative Hierarchical Model for DSM-VA large body of research has sought to explicate the underlying structure of the mood and anxiety disorders. This research has been stimulated by two key taxonomic problems: comorbidity and heterogeneity. Comorbidity can be broadly defined as the cooccurrence of different disorders within the same individual (see Lilienfeld, Waldman, & Israel, 1994;Mineka, Watson, & Clark, 1998); it reflects the empirical overlap between constructs that are hypothesized to be distinct. Therefore, when comorbidity occurs at greater than chance levels in the population, it raises the more general issue of discriminant validity. Evidence of significant-often substantial-comorbidity among DSM disorders has led to the development of increasingly sophisticated models that attempt to account for these patterns of co-occurrence (see Mineka et al., 1998).In contrast, heterogeneity results when phenomena that ordinarily are collapsed together are found to be sufficiently distinctive to warrant their separation; in the nosological context, this frequently results in the creation of diagnostic subtypes, which is an acknowledgment that an existing taxonomic category is too heterogeneous to be maximally informative (Watson, 2003b). This type of evidence has stimulated research into the symptom dimensions underlying many of the anxiety and mood disorders, including posttraumatic stress disorder (PTSD), obsessive compulsive disorder (OCD), and specific phobia (see Watson, Gamez, and Simms, in press).In this paper, I will review this structural evidence and explore its broader implications for the classification of the mood and anxiety disorders in DSM-V. I begin by explicating the logic of the current DSM-IV (American Psychiatric Association [APA], 1994) classification scheme for these disorders; to highlight significant problems with the current taxonomy, I will recast it as a quantitative structural model. I then review earlier structural models of this domain and discuss how they attempted to address...

Development and Evaluation of the Dutch Clinician-Administered PTSD Scale for DSM-5 (CAPS-5)

“…The Anhedonia model draws upon theoretical and empirical evidence that besides re-experiencing and avoidance, anxious and dysphoric arousal are two separate symptom clusters (Arnberg, Michel, & Johannesson, 2014; Witte, Domino, & Weathers, 2015), and negative affect and decreased positive affect or anhedonia are two unique constructs (Cuthbert & Kozak, 2013; Watson, 2005, 2009; Watson, Clark, & Stasik, 2011). Importantly, the six clusters of the Anhedonia model represent a further refinement within the clusters of the DSM-5 model for PTSD.…”

“…Another proposal, different from either the broad DSM-5 or narrow ICD-11 definition of PTSD, is an ‘hierarchical model’ in which PTSD would be composed of a higher-order dysphoria factor with symptoms shared with other mood and anxiety disorders and a lower-level PTSD factor with PTSD specific (core) symptoms. This would allow the possibility to examine the aetiology and pathogenesis of PTSD within an integrative model for mood and anxiety disorders (Hunt et al, 2017; Rademaker et al, 2012; Watson, 2005). Ultimately, it seems that more research is needed to determine which PTSD model best captures PTSD symptomatology and is clinically most meaningful.…”

Further validation of the IDAS: Evidence of convergent, discriminant, criterion, and incremental validity.

“…In discussing these data, it is important to emphasize that valid measures of depression and anxiety should not be completely independent of one another, but rather should be significantly interrelated (Clark & Watson, 1991;Watson, 2005).…”

“…All of these scales tap variance that is strongly related to the general distress/negative affectivity dimension that lies at the heart of the unipolar mood and anxiety disorders (see Clark & Watson, 1991;Mineka et al, 1998;Watson, 2005;Watson et al, 2007). All of these scales, therefore, should be significantly associated with a broad range of diagnoses, but should display particularly strong links to distress-based disorders such as major depression and generalized Further Validation of the IDAS 8 anxiety disorder (GAD; see Watson, 2005). We expected that the other IDAS scales would show weaker-but significant-associations with depression and GAD.…”

“…These total scores are valuable in many contexts; nevertheless, this focus on global dysfunction ignores the heterogeneous and multidimensional nature of depressive symptoms, and it hampers the identification of meaningful subtypes (Ingram & Siegle, 2002;Joiner et al, 2005). In contrast, the IDAS was specifically designed to contain multiple scales assessing specific symptoms of depression (e.g., insomnia, suicidality, appetite loss).Second, extensive evidence has established that these depression measures are very strongly associated with symptoms of anxiety (e.g., Clark & Watson, 1991;Mineka, Watson, & Clark, 1998;Watson, 2005). Consequently, the original IDAS item pool contained a broad range of anxiety-related symptoms.…”