Psychosis risk screening in youth: A validation study of three self-report measures of attenuated psychosis symptoms
Introduction
Despite advances in identification and treatment, schizophrenia and other psychoses continue to have a devastating impact. The average age of onset appears to be early adulthood, with most individuals on a trajectory toward psychosis experiencing some symptoms during adolescence (Cornblatt et al., 2009). A substantial body of research indicates that early intervention is associated with better treatment response, whereas a longer duration of untreated psychosis predicts poorer outcomes for those struggling with psychotic illness (Marshall et al., 2005). The association between duration of untreated psychosis and illness course highlights the need for advances in early identification.
Structured interviews for evaluating psychosis risk such as the Structured Interview for Psychosis Risk Syndromes (SIPS; Miller et al., 1999, Miller et al., 2003) and the Comprehensive Assessment of At-Risk Mental States (CAARMS; Yung et al., 2005) have contributed substantially toward creating a reliable and valid system for identifying risk prior to psychosis onset. These assessments evaluate psychosis risk largely through the identification of attenuated positive symptoms, sometimes referred to as the “At-Risk Mental State” (ARMS) or the “Attenuated Psychosis Syndrome” (APS). Programs of high-risk identification have been replicated by independent groups, yielding rates of prediction accuracy ranging from 16 to 52% with regard to psychosis onset within two years of meeting ultra-high risk criteria (Cannon et al., 2008, Yung et al., 2008, Correll et al., 2010, Ruhrmann et al., 2010). Despite some successes with high-risk identification, APS-based paradigms require further refinement before they can be responsibly incorporated in community settings (Fusar-Poli and Yung, 2012).
The ability to identify high-risk individuals through low-cost, brief, reliable methods is essential to the success of efforts to refine the APS construct. Clinician-administered interviews such as the SIPS require specialized training and are too labor-intensive to be used for screening or brief assessment purposes. Additionally, the positive predictive values obtained through interview-based assessments have been variable (Correll et al., 2010). The expanded use of screening tools might serve to address some of these concerns. Brief assessments capable of identifying individuals with APS may provide a methodological advantage with respect to recruiting samples high in the construct of interest. Increased outreach to potentially vulnerable populations through clinical screening can potentially yield more accurate and comprehensive detection of individuals on a progression toward psychosis.
Researchers have developed several self-report instruments targeting APS. These screeners have received varying amounts of validation, with each measure showing strong convergence with clinician interviews in independent samples (Miller et al., 2004, Ord et al., 2004, Kobayashi et al., 2008, Loewy et al., 2011, Jarrett et al., 2012). As validation samples may vary with regard to clinical and demographic characteristics, it is difficult to directly compare these measures' relative agreement with interview-based risk status. A study examining the convergence of several measures in the same sample suggested that APS screening tools demonstrate acceptable convergent and discriminant validity with one another relative to measures targeting different constructs (Kline et al., 2012). This study did not, however, incorporate a clinician-based interview. No study to date has examined the relations between several simultaneously-administered screening measures and interview-based APS status in an effort to determine which measure relates most strongly to a “gold-standard.” Such work might provide clues as to which screener has the most real-world clinical utility.
The aim of the current study is to explore the relative validity of three APS screening questionnaires by determining the accuracy of each screener with regard to SIPS diagnosis in a clinical sample. Three brief self-report instruments (Prodromal Questionnaire-Brief, Loewy et al., 2011; Youth Psychosis At-Risk Questionnaire, Ord et al., 2004; Prime Screen, Miller et al., 2004) were administered prior to the SIPS in a sample of youth receiving mental health services in order to determine the level of agreement between self-report responses and clinician ratings on each of the three screeners.
Section snippets
Procedures
All procedures received Institutional Review Board approval at the University of Maryland, School of Medicine and University of Maryland, Baltimore County. After providing informed consent (for minors, assent), participants completed the three APS self-report tools. Screeners were presented in a Latin Square design (i.e., the order of the three screening tools varied such that participants were randomly assigned to complete each measure either first, second, or third) to enable detection of
Descriptive statistics
All continuously-scored measures demonstrated reasonable normality (Curran et al., 1996).2 To detect possible order effects,
Discussion
The primary aim of the study was to evaluate the relative agreement of three APS screening instruments with the SIPS by administering measures concurrently within a sample of youth seeking mental health services. As continuous measures of APS, all three screeners correlated highly with the interview-based criterion. As dichotomous predictors of SIPS-diagnosed psychosis risk status, their performance was acceptable, although somewhat hampered by a high rate of false-positives and lower than
Role of the funding source
This work was supported in part by a Research Seed Funding Initiative (RSFI) grant from University of Maryland, Baltimore County, and by the Division of Child and Adolescent Psychiatry within the University of Maryland.
Contributors
Emily Kline and Gloria Reeves contributed to study design and data analysis. Camille Wilson, Sabrina Ereshefsky, Danielle Denenny, Elizabeth Thompson, and Kristin Bussell oversaw protocol implementation and data management. Steven Pitts assisted in the design of the study and served as a statistical consultant. Jason Schiffman was Principal Investigator for this project and assisted with all stages of design, implementation, analysis, writing, and editing. All authors contributed to and have
Conflict of interest
The authors do not have any actual or potential conflicts of interest to report.
Acknowledgments
None.
References (28)
- et al.
Subjective quality of life in subjects at risk for a first episode of psychosis: a comparison with first episode schizophrenia patients and healthy controls
Schizophr. Res.
(2005) - et al.
Prodromal interventions for schizophrenia vulnerability: the risks of being ‘at risk’
Schizophr. Res.
(2005) - et al.
Should attenuated psychosis syndrome be included in DSM-5?
Lancet
(2012) - et al.
Identifying men at ultra high risk of psychosis in a prison population
Schizophr. Res.
(2012) - et al.
Convergent and discriminant validity of attenuated psychosis screening tools
Schizophr. Res.
(2012) - et al.
A self-reported instrument for prodromal symptoms of psychosis: testing the clinical validity of the PRIME Screen-Revised (PS-R) in a Japanese population
Schizophr. Res.
(2008) - et al.
Psychosis risk screening with the prodromal questionnaire — brief version (PQ-B)
Schizophr. Res.
(2011) - et al.
Screening for prodromal adolescents in an isolated high-risk population
Schizophr. Res.
(2004) - et al.
Validation of ‘prodromal’ criteria to detect individuals at ultra high risk of psychosis: 2 year follow-up
Schizophr. Res.
(2008) - et al.
At clinical high risk for psychosis: outcome for nonconverters
Am. J. Psychiatry.
(2011)
Treated incidence of first-episode psychosis in the catchment area of EPPIC between 1997 and 2000
Acta Psychiatr. Scand.
Treatment history in the psychosis prodrome: characteristics of the North American Prodrome Longitudinal Study cohort
Early Interv. Psychiatry
Prediction of psychosis in youth at high clinical risk: a multisite longitudinal study in North America
Arch. Gen. Psychiatry
Schizophrenia: etiology and neurocognition
Cited by (88)
Longitudinal and cross-sectional validation of the WERCAP screen for assessing psychosis risk and conversion
2022, Schizophrenia ResearchSuicidal thoughts and behavior (STB) and psychosis-risk symptoms among psychiatrically hospitalized adolescents
2020, Schizophrenia Research