Experiencing nature promotes recovery from crisis better than taking a walk or interacting with friends, and the benefits may be larger for those who are suffering the most. People with many experiences of nature are less affected by their crisis than those who have few such experiences.
Ottosson, Johan, and Patrik Grahn. (2008). The role of natural settings in crisis rehabilitation: How does the level of crisis influence the response to experiences of nature with regard to measures of rehabilitation? Landscape Research, 33(1), 51-70.