intron, < 3 samples per group, and required at least 20 reads, which resulted in 18,685 unique genes across human brain regions. Human differential splicing analyses covaried for sex, age, brain pH, PMI, and smoking status. Note leafcutter performs analyses at the cluster level calculating a cluster p-value and then performs a Benjamini–Hochberg False Discovery (BH-FDR) multiple testing correction. Differentially spliced genes/clusters were those that survived a standard BH-FDR adjusted p-value < 0.05. We corrected p-values for multiple testing within brain regions and thus, our analyses do not account for multiple testing across tissues or samples. Since only 21 genes were differentially spliced in primates (BH-FDR < 0.05), we defined significant differential splicing with a nominal p-value threshold < 0.05. When possible, primate differential splicing analyses controlled for age (NAc sample). We assessed linear correlations of the ΔPSI across all significant alternative splicing events that were common across brain regions.
