One of the women I work with suffers from depression. This is something she has been living with since her late teens. She is in her late 40s now, and she says she has learned to deal with her symptoms of depression better now. Depression can cause a long list of physical ailments, but she tells me that she has a lot of oral issues that are associated with her depression.
And one of these issues is saliva production and salivary stones. After reading this article I can see the relationship between her depression and the salivary gland stones. She says she has a tough time getting out of bed sometimes, and she sometimes goes too long without eating and drinking. Because of this she gets dehydrated, and this is probably what causes the buildup in her salivary gland.