A systematic review on definitions and assessments of psychotic‐like experiences

Abstract

The variations in definitions and assessment tools of PLEs might contribute to mixed findings in researches. Reaching to a consensus through the study of phenomenology of PLEs is essential to further advancement of the research in this area.

Cannabis use as a risk factor for psychotic‐like experiences: A systematic review of non‐clinical populations evaluated with the Community Assessment of Psychic Experiences

“…These findings are in accordance with the hypothesis of gene‐environment interaction in the psychosis aetiology (Henquet, Di Forti, Morrison, Kuepper, & Murray, ; Linscott & van Os, ; van Os et al, ). Similarly, although it was only investigated in 1 study in this review, in schizotypal and schizoid personality disorders, PLEs may be a component of the main diagnosis (Honings et al, ; Lee et al, ; Mark & Toulopoulou, ).…”

“…One limitation for comparison of results from studies on psychotic manifestations in the general population is that the definition of PLE varies considerably, and there is a significant range of criteria and instruments that have been used to assess PLEs, which may at least partly explain the wide variation found in the prevalence of PLEs (Lee et al, ). Moreover, some studies adopted the term PLE as being synonymous with other conditions, such as ultra‐high risk of psychosis (Fusar‐Poli et al, , ) and attenuated psychosis syndrome (Lee et al, ; Yung, Phillips, Yuen, & McGorry, ), which are conditions associated with socio‐functional loss and cognitive impairment, and schizotypal and schizoid personality traits, which refer to a behavioural pattern, even if inconsistent, and not to sporadic or unusual experiences. This lack of uniformity in defining and measuring psychotic manifestations may have also hampered estimations of the strength of the association between cannabis use and PLE (Lee et al, ; Linscott & van Os, ).…”

“…In recent years, a growing number of studies have used a standardized assessment of PLE, the Community Assessment of Psychic Experiences (CAPE), designed specifically to evaluate PLEs in epidemiological studies in the general population (Stefanis et al, ; Verdoux & van Os, ). The CAPE, in its original version, contains 42 items, which evaluates PLEs as a lifetime occurrence, its frequency and impact on global functioning based on a dimensional approach (Lee et al, ; Stefanis et al, ). This dimensional view adopts the concept that a psychosis phenotype is a variation of discrete but related symptoms and indicates that psychotic symptoms may extend into the general population as observed in other mental disorders, such as depressive and anxiety disorders.…”

Screening for psychosis risk among adolescents in Child and Adolescent Mental Health Services: a description of the first step with the 16‐item version of the Prodromal Questionnaire (PQ‐16)

“…Furthermore, self‐reported PLEs are many times higher than those obtained from interview‐based assessments , , Depending on differences between definitions and assessment tools, their prevalence ranges from 7.5% to 40% , , , …”

Review of assessment tools for psychotic‐like experiences misses the psychosis‐like symptoms semi‐structured interview (PLIKSi) in ALSPAC

“…It was with great interest that we read the review entitled 'A systematic review on definitions and assessments of psychotic-like experiences' by Lee et al 1 in Early Intervention in Psychiatry. The authors highlight an important issue in the study of psychotic-like experiences (PLEs) that illustrates the importance of reaching clear definitions on the phenomenology of PLEs and clarity in the description of assessment tools.…”