Lemon balm is in the mint family, and it has a soapy, citrusy odor. There is some research[verification needed] showing it to be a calming aromatic for some people, in particular agitated Alzheimer's patients. It does not work for everyone, but it works for some. It is very vigorous, which is to say, some of your neighbors might not be too happy with you for planting it. But if you have good tilth, it is not that hard to get it out, and you will at least feel rather clean after wrestling with it.