GLP-1 and GLP-1 receptor antagonists have been found to have a sedative or anxiolytic effect on the mammalian central nervous system. Conversely, GLP-1 and GLP-1 receptor agonists increase nervous system activity and the stress response. The invention relates, in one aspect, to the use of GLP-1 agonists and antagonists to modulate the stress response in a mammal. In an aspect GLP-1 and GLP-1 receptor antagonists are used to treat stress-related disorders.