From Social Adversity to Suspicious Minds: Tracing Correlates and Trajectories of Paranoia in Adolescence

Paranoia is increasingly recognised as a dimensional and transdiagnostic phenomenon during adolescence, yet its developmental trajectory, cross-cultural expression, and socio-cognitive underpinnings remain insufficiently understood. This thesis presents four interrelated studies examining the phenomenology, correlates, and longitudinal dynamics of paranoid ideation across UK and Indonesian adolescent populations. Study 1, a systematic review and meta-analysis of 95 articles encompassing 273,665 adolescents from 22 countries, confirmed paranoia as a multidimensional and prevalent phenomenon, demonstrating robust associations with stress, anxiety, depression, and bullying, underscoring the need for culturally sensitive assessment. Study 2, a cross-sectional study of 604 British adolescents, demonstrated strong bidirectional associations between social anxiety and persecution paranoia. It also established that bullying and discrimination function as direct antecedents of persecution paranoia independently of threat sensitivity, which is a mechanistic pathway distinct from predicting social anxiety. Study 3 validated the Indonesian translation of the Revised Green et al. Paranoid Thoughts Scale (R-GPTS), confirming its two-factor structure and scalar measurement invariance across gender. It also revealed that Indonesian adolescents endorsed higher paranoia levels than comparable UK samples, with social anxiety as the strongest concurrent predictor. Study 4, a four-wave longitudinal study of 1,272 Indonesian secondary school students, identified bullying and discrimination as the strongest prospective predictors of persecution paranoia, with social anxiety and intolerance of uncertainty forming mutually reinforcing cycles. Growth mixture modelling revealed predominantly stable, moderate paranoia trajectories that exceeded Western prevalence rates, and showed that paranoia prospectively predicted a decline in self-esteem rather than the other way around. Collectively, these findings support the role of adversity in the development of paranoia, underscore its transdiagnostic and bidirectional nature, and emphasise the importance of cultural context in shaping paranoid ideation during adolescence. The implications for culturally sensitive assessment and early intervention are discussed.