Investigating key mechanisms mediating the relationship between social anxiety and paranoia: A 3-month follow-up cross-cultural survey conducted in Thailand and the United Kingdom

Abstract

Because there is no evidence-based intervention for social anxiety in psychosis, and mechanisms of social anxiety-paranoia continuum remain to be elucidated. We aimed to investigate mediators between social anxiety and persecutory paranoia in a prospective cross-cultural analogue sample using interventionist-causal models to guide developments of new treatments for psychosis. This is a prospective online survey included participants aged ≥18-year-old in Thailand and the UK. Participants completed questionnaires at baseline (T1) and 3-month follow-up (T2) measuring social anxiety, paranoia, depression and mediators (stigma; internal and external shame; social rank; self-esteem; and safety behaviours). We used mediation analysis with 10,000 bootstrapping bias-corrected 95% confidence intervals (CI) to test indirect effects. At baseline, 842 participants completed the survey, and 336 Thai and 369 UK participants agreed to follow-up. Of these, 186 (70.4%female; mean age 34.9 ​± ​9.1) Thai and 236 (81.4%female; 35.7 ​± ​12.7) UK participants completed the survey at follow-up. A multiple mediation model (controlling for T1 depression and T1 paranoia and T2 social anxiety) showed significant indirect effects for change score (T2-T1) in external shame. These cross-cultural data suggest that external shame may mediate the prospective relationship between social anxiety and paranoia. Further research should focus on mechanistic approach to test the finding in psychosis. • A cross-cultural sample showed consistent links between social anxiety and paranoia. • Paranoia, social anxiety and depression at baseline predicted paranoia at follow-up. • Changes in stigma, external shame and safety behaviours predicted paranoia at follow-up. • External shame mediated the association between social anxiety and paranoia. • External shame may be a key therapeutic target for paranoia treatments.