Causal Associations Between Ankylosing Spondylitis and 36 Common Mental Disorders: A Two-Sample Mendelian Randomization Study

Abstract Ankylosing spondylitis (AS) onset is often accompanied by psychiatric symptoms. In this study, two-sample Mendelian randomization (MR) was used to explore the genetic associations between AS and mental disorders. In this study, AS was regarded as exposure, and 36 mental disorders were regarded as outcomes. All the data were from the 7th version of the FinnGen GWAS summary data. Inverse-variance weighted (IVW), MR‒Egger regression, weight median, simple mode, and weight mode methods were used to determine the genetic associations. The Cochrane Q test, Egger-intercept test, MR pleiotropy residual sum and outlier, and leave-one-out tests were performed for sensitivity tests. The IVW results showed that AS was positively associated with autism, insomnia, depression, bipolar disorder, delirium, anankastic personality disorder, generalized anxiety disorder, anxious personality disorder, and mental and behavioral disorders due to opioids, hallucinogens, sedatives or hypnotics; AS was inversely associated with schizophrenia, persistent delusional disorder, and sexual dysfunction. The sensitivity tests showed these results were stable and robust. This study provides a theoretical basis for the early diagnosis of common mental disorders in patients with AS. It also provides evidence for the impact of inflammation on the central nervous system.