An article from latest The Week magazine.
http://theweek.com/article/index/226196/how-electr...on-can-change-the-way-we-think
This is from one comment ("Dr. Fugedy") .....
" ....I have used tDCS to provide relief for treatment-resistant chronic pain, migraine and depression for the last 5 years ..."
Not an herb, but maybe 'natural' when achieved by ... meditation, single point focus, 'drawing on the right side of the brain', 'Flow', etc. A tie-inn to People Care somewhere in here.....?