M87. PREVALENCE OF AUTOIMMUNE DISEASES IN INDIVIDUALS WITH PRIMARY PSYCHOTIC DISORDERS AT BOSTON MEDICAL CENTER

BACKGROUND: The prevalence of autoimmune diseases is higher among individuals with psychiatric illnesses than in the general population. It is unknown if the prevalence of autoimmune diseases differs among people with different primary psychotic disorders. Our objective was to assess whether the prevalence of autoimmune diseases differs among people with schizophrenia/schizoaffective disorder, affective (bipolar/depression) psychosis, and other psychotic disorders (delusional, brief psychotic, schizophreniform, or unspecified psychosis). METHODS: For our cross-sectional study, we used International Classification of Diseases (ICD) codes to identify individuals with primary psychotic disorders/unspecified psychoses who received treatment at Boston Medical Center between October 2003 and May 2019. Individuals with other/unspecified psychosis with an organic cause and individuals with unspecified psychosis, brief psychotic disorder with coinciding drug withdrawal, post-partum psychosis, or drug-induced mental illness, confusion, or seizure were excluded. Autoimmune diseases were categorized as systemic or as one of seven organ-specific subgroups (dermatological, endocrinological, gastroenterological, hematological, non-systemic connective tissue, and neurological). Multivariable logistic regression was used to compare differences in prevalence of autoimmune diseases among individuals with different psychoses adjusting for age, sex, and race. We also considered sex and race-stratified analyses. RESULTS: Of the 13,938 individuals (mean age = 43 years; 58% male) diagnosed with psychosis, 55% had schizophrenia, 17% had affective psychosis, and 29% had other/unspecified psychosis. Overall, nearly 9% of individuals with psychosis had at least one autoimmune disease (8% with schizophrenia, 11% with affective psychosis, and 8% with other/unspecified psychosis). The most prevalent autoimmune disease subgroups were systemic (39%), dermatological (26%), and endocrinological (23%). Compared to individuals with schizophrenia, individuals with affective psychosis had increased odds of having any autoimmune disease (OR: 1.38; 95% CI: 1.17, 1.63), dermatological autoimmune diseases (OR: 1.55; 95% CI: 1.15, 2.07), or endocrinological autoimmune diseases (OR: 1.56; 95% CI: 1.14, 2.12). Compared to individuals with schizoaffective as the only psychosis diagnosis, individuals with affective psychosis had increased odds of having any autoimmune disease (OR: 1.31; 95% CI: 1.03, 1.66) and individuals with schizophrenia had decreased odds of having neurological autoimmune diseases (OR: 0.46; 95% CI: 0.23, 0.96). Among individuals with any psychotic disorder, females were 95% more likely to have any autoimmune disease (OR: 1.95; 95% CI: 1.72, 2.20). No racial differences were observed overall; however, compared to individuals who identified as white, individuals who identified as Black, Hispanic, and Asian had decreased odds of having gastroenterological autoimmune diseases (OR: 0.52; 95% CI: 0.35, 0.76), neurological autoimmune diseases (OR: 0.32; 95% CI: 0.10, 0.83), and systemic autoimmune diseases (OR: 0.25; 95% CI: 0.04, 0.80), respectively, while Black individuals had increased odds of having systemic autoimmune diseases (OR: 1.45; 95% CI: 1.17, 1.81). DISCUSSION: The prevalence of autoimmune diseases varied among people with different primary psychotic disorders, and certain associations were modified by sex and race. Clinicians may consider additional screening for autoimmune diseases among individuals with psychosis.