Several other significant genetic correlations are supported in the clinical and epidemiological literature. For example, we found a positive correlation between ADHD and rheumatoid arthritis (rg = 0.16 ± 0.05, p = 9.0×10−4); this finds support in large registry-based studies indicating an increase in ADHD diagnosis in individuals with autoimmune disease (Nielsen et al. 2017), children with mother’s affected by autoimmune disease (Nielsen et al. 2017), and children of mothers with rheumatoid arthritis (Instanes et al. 2017). Registry-based studies also provide support for increased incidence of ear infections (rg = 0.20 ± 0.05, p = 2.0×10−4) and psoriasis (rg = 0.23 ± 0.07, p = 1.0×10−3) among individuals with ADHD (Adesman et al. 1990; Silva et al. 2014; Hegvik et al. 2017; Nielsen et al. 2017). On the other hand, ADHD was positively correlated with CRP (rg = 0.23 ± 0.06, p = 2.0×10−4), though a relatively large epidemiological study finds no association in affected individuals (Vogel et al. 2017). The negative correlation between anorexia nervosa and CRP (rg = −0.30 ± 0.08, p = 1.0×10-4) is borne out in
