I think that genetics plays a huge role in depression. And the combination of genetic predisposition combined with circumstance can overwhelm and throw one into a depression (as it did with me).

When I am very depressed I try very hard not to let anyone know how depressed I am. I don't wallow. This most recent depression I was able to tell T, and H both. I think this was the first time I was able to state my needs and how I felt and that I needed help.