Mental illness stigma in Iran: a national survey of public attitudes and contact effects using the Persian Opinion toward the Mentally Ill scale

Stigma remains a major barrier to mental-health care in Iran, nationally distributed sample of Iranian adults assessments using validated tools are scarce. We assessed public attitudes with the Persian Opinion toward the Mentally Ill (OMI) scale and examined demographic correlates and item-level associations with prior psychiatric contact. We conducted a cross-sectional online survey (late 2023-early 2024) of adults across Iran; only complete submissions were retained ( N = 4,360). Attitudes were measured with 22 OMI items. Factor analysis supported three domains, Social Distance/Acceptance, Stereotypes/Misconceptions, and Treatment/Help-seeking; the latter was retained with caution. An Overall Acceptance Index was computed as the mean of z-standardized domain scores. Group differences (gender, education, healthcare-worker [HCW] status) and adjusted models were estimated; item-level linear models tested associations with four contact types (self/relative; inpatient/outpatient). Domain means indicated moderate social closeness (M = 3.25, SD = 0.69) and high rejection of stereotypes (M = 4.14, SD = 0.51) and positive treatment beliefs (M = 4.14, SD = 0.53). The Overall Acceptance Index was standardized with M = 0.00 (SD = 0.75). Top-2-Box acceptance rates averaged 59.1%, with highest rates for treatment/help-seeking items (~ 84.7%) and lowest for social closeness/willingness (~ 36.4%). Females demonstrated slightly higher overall acceptance than males (Cohen’s d = 0.13); HCW scored significantly higher acceptance (d = 0.53); acceptance increased with educational attainment. In adjusted models controlling for all three predictors, significant main effects persisted; Education F(4,4353) = 15.59, p < 0.001, partial η²=0.014; HCW status F(1,4353) = 35.59, p < 0.001, partial η²=0.008. Prior contact analyses revealed distinct item-level patterns; Relative’s inpatient treatment most strongly predicted willingness for close social contact (β = 0.16–0.33, p < 0.01); self-outpatient contact linked to greater help-seeking endorsement and reduced stereotypes; relative-outpatient contact showed mixed effects, including paradoxically lower acceptance on some stereotype items (β=-0.09 to -0.11, p < 0.01). In this large online sample of Iranian adults, acceptance was high for treatment and stereotype rejection but lower for close interpersonal contact. Education, HCW status, and certain forms of prior contact showed small but consistent associations with greater acceptance. These modest associations identify potential targets for culturally adapted anti-stigma efforts while underscoring that most variance in public attitudes remains unexplained by the variables examined. Not applicable.