The schizotaxic self: phenotyping the silent predisposition to schizophrenia spectrum disorders

Childhood schizotypal features vs. high-functioning autism spectrum disorder: Developmental overlaps and phenomenological differences

Although autism spectrum disorder and schizophrenia have allegedly different onset timelines (e.g. in early years of life vs adolescence/early adulthood), there is nonetheless a diagnostic grey-zone along developmental stages, in which overlapping clinical features related to social impairment and oddity could impact on the differential diagnosis between childhood schizotypal features and high-functioning autism spectrum disorder. A phenomenological perspective may be helpful for the purpose of timely differential diagnosis also in developmental years.

Uncanny Mirroring: A Developmental Perspective on the Neurocognitive Origins of Self-Disorders in Schizophrenia

Varieties of anomalous subjective experiences, i.e. "basic self-disorders" (SDs), have been empirically demonstrated as core clinical features of schizophrenia spectrum disorders, predating full-blown psychotic symptoms. However, the clinical stage in which SDs emerge and their putative neurocognitive origins remain unsolved issues. Focusing on a prototypical anomalous mirror experience (i.e., a stable, trait-like subjective feeling of nonexisting while looking at oneself in the mirror) reported by an 11-year-old boy at familial high risk for schizophrenia and diagnosed as attenuated psychosis syndrome, we outline some possible developmental pathways leading to SDs. Such pathways are hypothesized in accordance with the documented early impairments in perceptual integration across distinct modalities in children at risk for schizophrenia spectrum disorders and to the specific features of mirror experience as provided by phenomenological and developmental psychology perspectives. We conclude that SDs could presumably have an early developmental origin, although children become progressively more aware of them. Although further hypothesis testing in clinical samples and longitudinal empirical investigation of at-risk children is badly needed, we propose that age-appropriate, phenomenologically oriented assessment of SDs could be useful for the early identification of psychotic risk.

Developmental vulnerability to psychosis: Selective aggregation of basic self-disturbance in early onset schizophrenia

Trait-like anomalies of subjective experience (aka, Basic Self-disturbance or Self-disorder, SD) have been empirically identified as schizophrenia-specific markers of vulnerability in several clinical and genetic high-risk populations. However, such specificity is still to be tested in developmental years, where emerging psychopathology is less crystallized and diagnostic boundaries more blurred. Thus, the current study explores the distribution of SD in adolescent help-seekers (age range 14 to 18) and tests the specificity of SD with respect to the severity of their diagnostic staging (Early Onset schizophrenia-spectrum psychosis [EOP], ultra high-risk [UHR] and clinical help-seeking controls [CHSC]). For this purpose, 96 help-seeking adolescents consecutively referred to specialized Child and Adolescent Units for diagnostic evaluation, underwent a comprehensive psychopathological examination including the specific interview for SD (i.e. the Examination of Anomalous Self-Experience, EASE). One-way ANOVA was used to test the diagnostic distribution of SD (EASE score), whereas multinomial logistic regression was used to test the effect of SD on the diagnostic outcome. SD frequency (both in terms of EASE total score and domain sub-scores) was decreasing progressively from EOP to CHSC, with intermediate levels in UHR. The EASE total score increased the risk of belonging to the more severe diagnostic stages (i.e, UHR and EOP vs CHSC as reference class) and allowed the correct reclassification of the 75% of the sample. The results confirm the schizophrenia-spectrum specificity of SD in adolescence, highlighting their potential value for early differential diagnosis and risk stratification.

The Self in the Spectrum: A Closer Look at the Temporal Stability of Self-Disorders in Schizophrenia

Self-disorders are temporally persisting, experiential anomalies of subjective experiences that index liability to schizophrenia. They impact on the temporal unfolding of concomitant, diagnostic symptoms and can be suitably characterized through the Examination of Anomalous Self Ex periences (EASE). Capitalizing on the results of a recent longitudinal study, we explored the relevant patterns of interaction within self-disorders' descriptive dimensions (i.e., stream of consciousness, presence, corporeality, demarcation, and solipsism). The results indicated that after a 5-year follow-up the interconnection across SD dimensions tightened, confirming that EASE domains are interdependent aspects of an overarching structural change of subjectivity.

Examination of anomalous self-experience: initial study of the structure of self-disorders in schizophrenia spectrum

A growing body of evidence points to the clinical and heuristic value of anomalous subjective experiences (ASEs) for the characterization of schizophrenia spectrum vulnerability and early detection purposes. In particular, a subgroup of ASEs, entailing basic disorders of self-awareness (self-disorders [SDs]), has been shown to constitute a core feature of both clinically overt and latent (schizotaxic) spectrum phenotypes. However, a major limitation for the translational implementation of this research evidence has been a lack of assessment tools capable of encompassing the clinical richness of SDs. Here, we present the initial normative data and psychometric properties of a newly developed instrument (Examination of Anomalous Self-experience [EASE]), specifically designed to support the psychopathological exploration of SDs in both research and "real world" clinical settings. Our results support the clinical validity of the EASE as a tool for assessing anomalies of self-awareness (SDs) and lend credit to the translational potential of a phenomenological exploration of the subjective experience of vulnerability to schizophrenia.

The silent side of the spectrum: schizotypy and the schizotaxic self

The identification of individuals carrying unexpressed genetic liability to schizophrenia is crucial for both etiological research and clinical risk stratification. Subclinical psychopathological features detectable in the nonpsychotic part of the schizophrenia spectrum could improve the delineation of informative vulnerability phenotypes. Inspired by Meehl's schizotaxia-schizotypy heuristic model, we tested anomalous subjective experiences (self-disorders, SDs) as a candidate vulnerability phenotype in a sample of nonpsychotic, genetically high-risk subjects. A total of 218 unaffected members of 6 extended multiplex families (assessed between 1989 and 1999 during the Copenhagen Schizophrenia Linkage Study) were stratified into 4 groups of increasing psychopathological expressivity: no mental illness (NMI), no mental illness with schizotypal traits (NMI-ST), personality disorders not fulfilling other personality disorders (OPDs), and schizotypal personality disorder (SPD). We tested the distribution of SDs among the subgroups, the effect of SDs on the risk of belonging to the different subgroups, and the effect of experimental grouping and concomitant psychopathology (ie, negative symptoms (NSs) and subpsychotic formal thought disorder [FTD]) on the chances of experiencing SDs. SDs distribution followed an incremental pattern from NMI to SPD. SDs were associated with a markedly increased risk of NMI-ST, OPDs, or SPD. The odds of SDs increased as a function of the diagnostic category assignment, independently of sociodemographics and concomitant subclinical psychopathology (NSs and FTD). The results support SDs as an expression of schizotaxic vulnerability and indicate a multidimensional model of schizotypy--characterized by SDs, NSs, FTD--as a promising heuristic construct to address liability phenotypes in genetically high-risk studies.