Associations Between Area Deprivation and Paranoia in Serious Mental Illness

BACKGROUND AND HYPOTHESIS: Though linked to paranoia in the general population and high-risk groups, neighborhood deprivation remains underexplored in serious mental illness. Paranoia also varies by demographic subgroup, potentially reflecting exposure to place-based disadvantage. Advances in the measurement of neighborhood deprivation and momentary experiences of suspiciousness could shed light on these relationships. This study uses neighborhood-level data to examine associations between area deprivation and paranoia in schizophrenia spectrum disorders (SSDs) and bipolar disorder (BD). STUDY DESIGN: Data from 293 participants with SSD (n = 148) and BD (n = 145) from three US sites were analyzed. Neighborhood disadvantage was quantified using the National Area Deprivation Index (ADI). Clinician-rated paranoia was assessed using the Positive and Negative Syndrome Scale; momentary feelings of threat/suspiciousness (MFTS) was measured across 30 days of Ecological Momentary Assessments (EMAs). Analyses examined the relationships between ADI and paranoia and tested if ADI explains observed demographic differences in paranoia. To assess specificity, hallucinations were examined in parallel. STUDY RESULTS: Greater neighborhood disadvantage was associated with higher clinician-rated paranoia and MFTS; no association was observed for hallucinations. Participants with SSD and those with racial backgrounds other than White had higher ADI scores and higher paranoia. The ADI-paranoia relationship did not differ in strength across clinical or demographic groups, nor across study sites. Area Deprivation Index significantly mediated the association between racial background and paranoia. CONCLUSIONS: Neighborhood deprivation is associated with paranoia but not hallucinations, supporting a specific link between environment and paranoia. Improvement of neighborhood-level conditions may offer a pathway to reducing paranoia and improving functioning.