Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): I. Psychosis superspectrum

Abstract

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a scientific effort to address shortcomings of traditional mental disorder diagnoses, which suffer from arbitrary boundaries between psychopathology and normality, frequent disorder co‐occurrence, heterogeneity within disorders, and diagnostic instability. This paper synthesizes evidence on the validity and utility of the thought disorder and detachment spectra of HiTOP. These spectra are composed of symptoms and maladaptive traits currently subsumed within schizophrenia, other psychotic disorders, and schizotypal, paranoid and schizoid personality disorders. Thought disorder ranges from normal reality testing, to maladaptive trait psychoticism, to hallucinations and delusions. Detachment ranges from introversion, to maladaptive detachment, to blunted affect and avolition. Extensive evidence supports the validity of thought disorder and detachment spectra, as each spectrum reflects common genetics, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, biomarkers, and treatment response. Some of these characteristics are specific to one spectrum and others are shared, suggesting the existence of an overarching psychosis superspectrum. Further research is needed to extend this model, such as clarifying whether mania and dissociation belong to thought disorder, and explicating processes that drive development of the spectra and their subdimensions. Compared to traditional diagnoses, the thought disorder and detachment spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and higher acceptability to clinicians. Validated measures are available to implement the system in practice. The more informative, reliable and valid characterization of psychosis‐related psychopathology offered by HiTOP can make diagnosis more useful for research and clinical care.

Transdiagnostic Dimensions of Psychiatric Comorbidity in Individuals at Clinical High Risk for Psychosis: A Preliminary Study Informed by HiTOP

“…Hypomania was another hybrid construct, as a component of higher positive symptoms but lower negative symptoms. There is some debate about transdiagnostic relationships between mania, thought disorder, and internalizing: is mania a component of internalizing, a component of thought disorder, a blend of both, or a separate dimension entirely ( 15 , 20 , 22 , 23 , 62 )? This study suggests a somewhat novel placement of (hypo)mania in the CHR state, as a component of thought disorder that in some way protects against detachment.…”

“…Indeed, symptom dimensions have consistently outperformed categorical diagnoses in explaining clinical outcomes in individuals with psychotic diagnoses (16,17). Recent research shows that a thought disorder/positive symptom dimension is clearly distinct from a detachment/negative symptom dimension; both dimensions can be further subdivided; and both dimensions relate to normative and abnormal personality processes (18)(19)(20)(21)(22)(23)(24)(25). Most of this work has focused on the structure of psychotic symptoms, and less is known about how these symptoms fit within broader transdiagnostic models of psychopathology such as HiTOP (15).…”

Pluripotential Risk and Clinical Staging: Theoretical Considerations and Preliminary Data From a Transdiagnostic Risk Identification Approach

“…Similar to RDoC, HiTOP represents a hierarchical, dimensional approach to psychopathology, with lower-level syndromes based on empirical covariation of signs and symptoms which form higher-level spectra based on covariation of syndromes (80)(81)(82). This idea is related to the concept of micro-and macro phenotypes first articulated by van Os (83).…”

Autoimmune encephalitis with psychiatric features in adults: historical evolution and prospective challenge

“…However, further studies should be conducted to elucidate the exact role of autoantibody subgroups and their correlation to psychopathology assessed via different psychometric approaches. In this sense, novel research tools for classification of psychopathology as the hierarchical taxonomy of psychopathology comprising spectra and subfactors (Ruggero et al 2019 ; Kotov et al 2020 ) apart from the standard assessment according to Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM V) are promising. Apart from the relationship between psychopathology and autoantibodies, the relationship between immune cell subsets as potential biomarkers of autoimmune encephalitis (Hansen et al 2020b , c ) is interesting, as a recent study demonstrated a potential role of cerebrospinal fluid B- and T-cell activity and cognitive dysfunction in suspected limbic encephalitis (Helmstaedter et al 2020 ).…”