I build mindmaps using freemind/freeplane to keep track of my research; I literally have hundreds of mindmaps from 3Dprinting to ZFS. I also link mindmaps to other mindmaps (crude "topic mapping").
I took St. John's Wort until my wife asked me stop since my personality was adversely altered to the point of being an a-hole. I wasn't able to discern the change. With that said, it's a good idea to have a third-party evaluating for possible side-effects. St. John's Wort is powerful.