Ashwagandha, brahmi, gotu kola, shatavari are some of the globally renowned herbs and extremely popular for anxiety and depression. These are known to produce the same effects as antidepressants and antianxiety meds without any side effects if taken cautiously and calm down the nervous system and promote sleep. Its easily available on amazon, eBay, etc. Some of the popular brands which I prefer is Himalaya, planet ayurveda, organic India, life extension and there are many many others

Ashwagandha has shown to promote regeneration of brain cells in recent studies