Prevalence and clinical relevance of interview-assessed psychosis-risk symptoms in the young adult community

Abstract

BackgroundAn efficient indicated prevention of psychotic disorders requires valid risk criteria that work in both clinical and community samples. Yet, ultra-high risk and basic symptom criteria were recently recommended for use in clinical samples only. Their use in the community was discouraged for lack of knowledge about their prevalence, clinical relevance and risk factors in non-clinical, community settings when validly assessed with the same instruments used in the clinic.MethodsUsing semi-structured telephone interviews with established psychosis-risk instruments, we studied the prevalence of psychosis-risk symptoms and criteria, their clinical relevance (using presence of a non-psychotic mental disorder or of functional deficits as proxy measures) and their risk factors in a random, representative young adult community sample (N=2683; age 16–40 years; response rate: 63.4%).ResultsThe point-prevalence of psychosis-risk symptoms was 13.8%. As these mostly occurred too infrequent to meet frequency requirements of psychosis-risk criteria, only 2.4% of participants met psychosis-risk criteria. A stepwise relationship underlay the association of ultra-high risk and basic symptoms with proxy measures of clinical relevance, this being most significant when both occurred together. In line with models of their formation, basic symptoms were selectively associated with age, ultra-high risk symptoms with traumatic events and lifetime substance misuse.ConclusionsPsychosis-risk criteria were uncommon, indicating little risk of falsely labelling individuals from the community at-risk for psychosis. Besides, both psychosis-risk symptoms and criteria seem to possess sufficient clinical relevance to warrant their broader attention in clinical practice, especially if ultra-high risk and basic symptoms occur together.

Psychosis‐risk criteria in the general population: frequent misinterpretations and current evidence

“…Thereby, the focus is predominately on the APS criterion 4 . A main reason for the disparity between clinically and epidemiologically based viewpoints obviously originates from differences in assessments.…”

“…A main reason for the disparity between clinically and epidemiologically based viewpoints obviously originates from differences in assessments. Until recently, epidemiological studies have mainly used self-rating questionnaires or standardized lay-person interviews for the assessment of "psychotic-like experiences" (PLEs) 4,5 , that are usually equaled to (attenuated) psychotic symptoms by critics 3 . Yet, questionnaire studies significantly overestimate the prevalence of PLEs already in comparison to lay-person interview studies 5 , and even more in comparison to clinician-based evaluations of APS using psychosis-risk assessment instruments 6 .…”

“…Indeed, the first sufficiently representative general population study (N52,683) of young adults (age 16-40) in whom psychosis-risk criteria 4 were assessed by trained clinicians -using established early detection instruments -documented that, although 11.96% (N5321) reported any lifetime and 7.53% (N5202) any current APS/ BIPS, only 0.56% (N515) fulfilled APS criteria (including onset or worsening within the past 12 months and at least weekly occurrence in the past month). One person meeting APS criteria also fulfilled BIPS criteria (including onset within the past three months and at least monthly occurrence for several minutes) 4 .…”

“…Another feature that psychosis-risk criteria share with mental disorders is their frequent co-occurrence with other disorders, in particular depressive and anxiety disorders, with a prevalence of 23-94% in clinical 1,2 and 45% in general population samples 4 . Arguing that APS are solely a marker of the severity of nonpsychotic disorders 3 disregards the fact that depression and anxiety often arise from other mental or somatic disorders 7 , including non-affective psychoses 8 .…”

“…COGDIS and APS are equally common in clinical 1,9 and community samples 4 , often co-occur and, together, convey a much increased risk for psychosis, but not for other mental disorders, in clinical samples 9 . Yet, for their distinct quality 1,4,10 , cognitive basic symptoms cannot be referred to as "low-grade psychotic symptoms" or "psychotic experiences" 3 and, consequently, critiques based on findings on PLEs cannot be extended to them.…”