Oral 14

[O-14-05] Validation of the Revised Green et al. Paranoid Thoughts Scale (R-GPTS) in Indonesian adolescents

*Dian Caesaria Widyasari^1,2, Tom Clark¹, Jessica Kinsgton³, Richard Bentall¹ (1.University of Sheffield(UK), 2.University of Muhammadiyah Malang(Indonesia), 3.Royal Holloway University of London(UK))

Keywords:

Adolescent,Paranoia,R-GPTS

Background: Brief self-reports can enhance the early detection of paranoia in adolescents, but such tools are often limited for non-English speaking populations. The Revised Green et al. Paranoid Thoughts Scale (R-GPTS) assesses paranoia through two subscales: Part A - ideas of reference (8 items), and Part B – ideas of persecution (10 items). This study examines the psychometric properties of the Indonesian translation of the R-GPTS, providing a concise self-report measure for Indonesian adolescents. Method: A convenience sample of 247 adolescents aged 14 to 18 from three secondary schools completed the R-GPTS, along with the Social Phobia Inventory (SPIN), the Rosenberg Self-Esteem Scale (RSES), the Inventory of Parent and Peer Attachment (IPPA), and the Brief Self-Report Measure of Adolescent Bullying. To evaluate model fit, confirmatory factor analysis was conducted using the Weighted Least Squares Mean and Variance adjusted (WLSMV) estimator. Results: Most participants were 16 (29.4%) and female (55.6%). The model showed adequate-to-good fit: CFI = .924, TLI = .913, RMSEA = .089, and SRMR = .070, confirming the two-factor structure. Internal consistency was acceptable for Part A (α = .78) and good for Part B (α = .87). Construct validity was demonstrated by significant positive relationships between bullying victimization and social anxiety with paranoia, while self-esteem and maternal attachment exhibited negative correlations with paranoia. The Indonesian version of the scale has been subsequently used in a 12-month longitudinal study with around 1,200 adolescents aged 15 to 18, exploring factors related to the development of paranoia symptoms over time. The baseline data from this cohort has confirmed the factor structure and properties of the scale. Conclusions: The Indonesian R-GPTS demonstrated satisfactory psychometric properties, supporting its use as a reliable tool for assessing paranoia in Indonesian adolescents.