Psychosis and Schizophrenia-Spectrum Personality Disorders Require Early Detection on Different Symptom Dimensions

Abstract

Psychotic disorders and schizophrenia-spectrum personality disorders (PD) with psychotic/psychotic-like symptoms are considerably linked both historically and phenomenologically. In particular with regard to schizotypal and schizotypal personality disorder (SPD), this is evidenced by their placement in a joint diagnostic category of non-affective psychoses in the InternationaI Classification of Diseases 10th Revision, (CD-10) and, half-heartedly, the fifth edition of Diagnostic and Statistical Manual of Mental Disorders, (DSM-5). Historically, this close link resulted from observations of peculiarities that resembled subthreshold features of psychosis in the (premorbid) personality of schizophrenia patients and their biological relatives. These personality organizations were therefore called “borderline (schizophrenia)” in the first half of the 20th century. In the 1970s, they were renamed to “schizotypal” and separated from psychotic disorders on axis-I and from other PD on axis-II, including modern borderline PD, in the DSM. The phenomenological and historical overlap, however, has led to the common assumption that the main difference between psychotic disorders and SPD in particular was mainly one of severity or trajectory, with SPD representing a latent form of schizophrenia and/or a precursor of psychosis. Thus, psychosis proneness and schizotypy are often assessed using SPD questionnaires. In this perspective-piece, we revisit these assumptions in light of recent evidence. We conclude that schizotypy, SPD (and other schizophrenia-spectrum PD) and psychotic disorder are not merely states of different severity on one common but on qualitatively different dimensions, with the negative dimension being predictive of SPD and the positive of psychosis. Consequently, in light of the merits of early diagnosis, the differential early detection of incipient psychosis and schizophrenia-spectrum PD should be guided by the assessment of different schizotypy dimensions.

The Relationship between PID-5 Personality Traits and Mental States. A Study on a Group of Young Adults at Risk of Psychotic Onset

“…Our results on Detachment would seem to be in line with the literature that considers the inclusion of the Avoidant Personality disorder as a Schizophrenia spectrum disorder [ 44 ]. According to some studies, Detachment is mildly manifested in the premorbid period as well as subthreshold negative symptomatology [ 45 ]. When in the literature Schizoid Disorder, which by definition has Detachment domain characteristics (although the disorder is not considered by the Alternative Model for DSM 5), was also considered, it was found that schizoid rather than schizotypal personality traits predicted conversion to psychosis in the UHR patient, mainly from deficit in social interaction [ 46 ].…”

Personality Traits and Disorders in Adolescents at Clinical High Risk for Psychosis: Toward a Clinically Meaningful Diagnosis

“…Looking at this picture as a Gestalt, it seems to tap into different dimensions of the schizotypy construct (47). The schizotypy construct refers to the continuum of positive, negative, and disorganized psychotic-like signs and symptoms, ranging from healthy to pathological, that has been theoretically considered-and empirically demonstrated-to predict schizophrenia-spectrum disorders (48)(49)(50). In particular, odd thinking and behaviors, unusual perceptual experiences, and suspiciousness could refer to positive symptoms of schizotypy, which are included in the UHR criteria.…”

Basic Symptoms Are Associated With Age in Patients With a Clinical High-Risk State for Psychosis: Results From the PRONIA Study

“…On the other hand, the model assumes that (B) unusual perceptual experiences or thought contents phenomenologically identical to APS might occur during childhood and early adolescence as an expression of not yet fully matured cognitive abilities (gray-shaded curve). If their maturation is impaired by risk factors or stressors (flashes) or neurodevelopmental disturbances in information processing (that might be experienced as BS), APS might persist or progress (dotted line), potentially leading to positive and potentially benign schizotypal traits (35), an Attenuated Psychosis Syndrome (36), and/or psychosis.…”