AIM: Personality Disorders (PD) often share clinical and phenomenological overlap with psychotic disorders, especially at onset. However, there is little research on comorbid PD among people experiencing first episode psychosis. We examined the prevalence of PD recording and its sociodemographic and clinical correlates in people accepted to Early Intervention in Psychosis (EIP) services. METHODS: Participants were aged 16-35, accepted into 6 EIP services for suspected psychosis, as part of the Social Epidemiology of Psychoses in East Anglia (SEPEA) study. PD was recorded by clinicians according to ICD-10. Multilevel logistic regression was performed. RESULTS: Of 798 participants, 76 people (9.5%) received a clinical diagnosis of PD, with emotionally unstable PD (75.0%, N = 57) the most common subtype. In multivariable analysis, risk factors for PD included female sex (odds ratio [OR]: 3.4; 95% CI: 2.0-5.7), absence of psychotic disorder after acceptance to EIP (OR: 3.0; 95% CI: 1.6-5.5), more severe hallucinations (OR: 1.6; 95% CI: 1.2-2.1), and lower parental SES (OR: 1.4; 95% CI: 1.1-1.8). Compared with the white British, black and minority ethnic groups were less likely to receive a PD diagnosis (OR: 0.3; 95% CI: 0.1-0.7). There was no association between PD and neighbourhood-level deprivation or population-density. CONCLUSIONS: Recording of a PD diagnosis was three times more common amongst participants later found not to meet threshold criteria for psychotic disorder, implying phenomenological overlap at referral which highlights difficulties encountered in accurate diagnostic assessment, treatment and onward referral. People with PD experienced more individual-level, but not neighbourhood-level social disadvantage in an already disadvantaged sample.