More Evidence Linking Autoimmune Diseases to Attention-Deficit/Hyperactivity Disorder

The evidence for bidirectional links between the immune system and the central nervous system has accumulated over the last few decades. One important area within this field of research is the association between maternal autoimmune diseases and mental disorders. Several previous epidemiologic studies have found autoimmune diseases to be associated with mental disorders, with the largest evidence base being for associations with schizophrenia,¹ bipolar disorder,² depression,³ and autism spectrum disorder,⁴ and much fewer studies having examined associations with attention-deficit/hyperactivity disorder (ADHD),⁵ tic disorders,⁶ and obsessive-compulsive disorder.⁷ Multiple potential mechanisms have been proposed for the association between maternal autoimmune diseases and mental disorders,⁸ and the article by Nielsen et al⁹ sums up the literature on this. Overall, these mechanisms are thought to include shared genetic and environmental risk factors or direct effects of maternal autoantibodies or cytokines crossing the placenta and altering the fetal immune response, which in turns leads to changes in the central nervous system.