The Joint Structure of Detachment and Internalizing Symptoms

The DSM nosological system has been criticized for problems related to disorder comorbidity, disorder heterogeneity, and artificial dichotomization. These problems lead to diagnostic instability, loss of information, and reduced communicability among clinicians, with implications for case conceptualization and the selection of treatment protocols. The Hierarchical Taxonomy of Psychopathology (HiTOP) nosological model, created in response to the DSM system, proposed that all psychopathology is subsumed within six spectra (Kotov et al., 2017). However, there are several issues regarding the validity of one of these spectra, detachment, including (1) the detachment spectrum is primarily characterized by personality disorders, possibly reflecting a method effect; (2) detachment and internalizing are both characterized by low extraversion and are distinguished by the additional presence of high neuroticism for internalizing, indicating that detachment and internalizing may be more similar than currently characterized in the HiTOP model; and (3) the personality profile of avoidant personality pathology (high neuroticism, low extraversion), currently classified in HiTOP as a detachment disorder, is actually more similar to internalizing psychopathology. These issues are consistent with past arguments that several (categorical) internalizing and detachment disorders actually represent the same syndrome with different severities. Therefore, the current study investigates the joint hierarchical structure of detachment- and internalizing-related content using data from an online community sample (N = 625) and a student sample (N = 450). Participants completed 532 HiTOP Phase 2 items related to internalizing and detachment, as well as the Faceted Inventory for the Five Factor Model (FI-FFM; Watson, Nus, & Wu, 2019). Results indicate that detachment-related content can be split into two unipolar constructs with (1) high detachment forming a separate, but highly interrelated factor with internalizing and (2) maladaptive extraversion forming a separate factor having mania-related content (labeled Reward Seeking). Internalizing was characterized by high neuroticism and low conscientiousness; in contrast, (high) detachment was characterized by low extraversion, and Reward Seeking was characterized by high extraversion and low agreeableness. On the basis of these results, I recommend that detachment be reclassified as an internalizing subfactor, rather than a standalone spectrum in the HiTOP model.