DDC and attention deficit-hyperactivity disorder: A previous study found that ASDZL significantly upregulated the expression of tyrosine hydroxylase and dopa decarboxylase, which are related to DA synthesis in the presynaptic membrane of SHR rats and increased the expression levels of synaptic-associated protein 25 and syntaxin-1A involved in the formation of SNARE complexes and vesicle-associated membrane proteins, among other protein and mRNA, thereby improving the core symptoms of ADHD [36].