Of the tested neuropsychiatric traits, we observed notable enrichment among high confidence fetal brain eQTL of variants associated with attention deficit hyperactivity disorder (ADHD), bipolar disorder, and schizophrenia. We also observed nominally significant enrichment of variants associated with autism at lower GWAS P value thresholds (Additional file 1: Table S7), although we note that the number of tested variants for this was smaller than for other brain-related traits, limiting statistical power. Like autism, ADHD is considered to be a neurodevelopmental condition, but the genes involved and the developmental timing of their action are largely unknown. We observed an average 13-fold enrichment of ADHD-associated variants within fetal brain eQTL across the four GWAS P value thresholds tested, suggesting an important prenatal genetic component to this condition. Our finding of an enrichment of schizophrenia-associated variants among fetal brain eQTL is also consistent with the long hypothesized early neurodevelopmental component to this disorder [11, 12]. Although less commonly conceptualized as neurodevelopmental in origin, we observed a similar enrichment of risk variants for bipolar disorder among high confidence fetal brain eQTL. In contrast, we
