Still more evidence is arising that Nature is a healing force when
approached respectfully. 
Washington State has developed a program enabling veterans suffering from PTSD to get involved with Nature in a mutually
healing way.  As they explain, 

The mission of the Veterans Conservation Corps is to 
assist
veterans by providing training and volunteer opportunities that 
help to
restore and protect Washington state’s natural resources.

Veteran have made connections there
that enable them to continue such relationships with Nature if they wish.  For example, by becoming organic
farmers. Perhaps one of the subtle maladies dragging down the sanity of our society is “Nature
Deficit Disorder.”   Certainly the brightest spot
in my own childhood was getting out alone in Nature.  My old classmate Richard Louv, who has written Last Child in
the Woods,   discusses NDD and its significance
here on NPR.