"Depression is a way of defending yourself against overwhelming thoughts and emotions, usually generated by childhood trauma.
Anything can be a defence, she says: drinking too much, getting into abusive relationships, anger, mania, getting very stressed.
Depression is brought to bear when there’s nothing else left in your armoury.
'It’s like a blanket over feelings that are unacceptable to the conscious mind.
 It absolves you of all responsibility to say ‘I have these feelings and I need to attend to them’."

Sally Willis, theguardian.com