A Transdiagnostic, Dimensional Classification of Anxiety Shows Improved Parsimony and Predictive Noninferiority to DSM.

The current conceptualization of anxiety in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)—which includes 11 anxiety disorders plus additional anxiety-related conditions—does not align with accumulating evidence that anxiety is transdiagnostic and dimensional in nature. Transdiagnostic dimensional anxiety models have been proposed, yet they measure anxiety at either a very broad (e.g., "anxiety") or very narrow (e.g., "performance anxiety") level, overlooking intermediate properties of anxiety that cut across DSM disorders. Using indicators from a well-validated semistructured interview of anxiety-related disorders, we constructed intermediate-level transdiagnostic dimensions representing the intensity, avoidance, pervasiveness, and onset of anxiety. We captured these content-agnostic dimensions in a sample representing varying levels and forms of anxiety (N = 268), including individuals with generalized anxiety disorder, social anxiety disorder, panic disorder, agoraphobia, specific phobia, separation anxiety disorder, posttraumatic stress disorder, and obsessive–compulsive disorder (n = 205) and individuals with no psychopathology (n = 63). In preregistered analyses, our dimensional anxiety model showed noninferiority to DSM-5 diagnoses in predicting concurrent and prospective measures of anxiety-related impairment, anxiety vulnerabilities, comorbid depression, and suicidal ideation. These results held regardless of whether the dimensions were combined into a single composite or retained as separate components. Our transdiagnostic dimensional model offers meaningful gains in parsimony over DSM, with no loss of predictive power. This project provides a methodological framework for the empirical evaluation of other transdiagnostic dimensional models of psychopathology that have been proposed as alternatives to the DSM. General Scientific Summary: The current classification of anxiety is cumbersome; does not align with evidence that anxiety problems cut across disorder categories; and fails to acknowledge that the severity of anxiety matters, even at low levels. We developed a new classification that distills key features of anxiety—intensity, avoidance, pervasiveness, and onset—across disorders, allowing any individual to be located along a gradient from none to severe for each feature. This transdiagnostic dimensional approach is much simpler than the current Diagnostic and Statistical Manual of Mental Disorders (DSM) approach to anxiety, incorporates information about severity, and performs just as well as DSM diagnoses in predicting important clinical outcomes. [ABSTRACT FROM AUTHOR]