The Trials and Turbulations blog has an interesting post about the relationship between low oxytocin levels and alcoholism.
Karen, the author, quotes Arthur Janov, inventor of Primal Therapy, who said that Alcoholics Anonymous meetings work because they help raise levels of oxytocin and suppress pain.
Conversely, if there had been love very early on, the levels would be high and pain levels low.There would have been no need to drink. So the support groups are patching up the lack generated early in life by the absence of love.
She also links to a study showing wounds healed faster in hamsters that had social contact with a sibling -- or isolated hamsters given oxytocin by injection. Gee, this makes me feel sorry for all the hamsters huddled alone in their little plastic cages.