Since we do not make enough BH4 (tetrahydrobiopterin) with this enzyme deficiency we cannot metabolize the amino acids needed to make serotonin, dopamine, and Nirtic Oxide. And then some of these amino acids turn into trace amines that act like meth.

https://jamanetwork.com/journals/jamaneurology/fullarticle/7...

https://www.frontiersin.org/files/Articles/382815/fnins-12-0...