Depression? Narcissist? Sociopath? Psychopath? Google is not my friend :-(

My partner suffers with long term clinical depression.

For the first three years of our on/off relationship, I didn't know anything about it, mainly because she'd made light of my ex-wife's depression, saying that I'd never encounter it with her because she comes from a background of 'pick yourself up and get on with it'. Looking back it was massive smokescreen. She has been keeping it secret for a long time, and I think she felt I would run a mile having come out of another relationship with a depressed partner.

We've broken up and got back together many times over the past five years. The pattern has been much the same. Communication dwindles on her side. We have a fight - verbal not physical - and then she cuts off all communication for months. I'm talking the absolute silent treatment. It's a long distance relationship, so there's no opportunity to just pop round, or to bump into one another, contrived or otherwise.

She told me in stages about her depression. The first major step was to leave her antidepressants where I would find them. The second, after three months of total silence, was to ring me out of the blue to tell me what she was going through wasn't my fault. Both those steps were in the past two years of a five year relationship, so the first three years, including break-ups, had some events and behaviours that I just couldn't fathom.

When I was left searching for answers as to why she had completely disappeared the first time round, it was put to me by more than one person that I may be involved with a sociopath and a narcissist. That the glorious honeymoon period was just to get me hooked, and all the cold treatment, including the silent treatment, was just to feed the narcissistic personality. Extremely hard to swallow, as the first year had been amazing, but a distinct possibility.

I am no expert, but there seemed to be too many examples of behaviour completely counter to what I understand sociopathic and narcissistic behaviour to be, and as you can imagine, I was desperate for the love of my life to not be someone who had set out with the sole intention of playing a huge game with me.

So when I started to research clinical depression, peri-menopausal depression, post-natal depression (particularly in highly successful women) - yes, I was on a Google rollercoaster like so may go on, I guess - I realised that looking back through the 'lens' of clinical depression, many of her behaviours made perfect sense. The notion of the narcissistic psychopath receded.

Right now we are in another of the long term silent treatment periods. I haven't heard a thing for six months. That's no replies to any forms of communication. Modern technology means I can see when things I send are read, but that doesn't mean they are not simply discarded or deleted.

So I guess my questions are, does anyone here who suffers with depression ever shut out their partner for months on end? Or would you, if they didn't share your home, or live locally (she lives 600 miles away)? Can a narcissist still suffer with clinical depression? Am I excusing unreasonable behaviour?

I'm not asking anyone to tell me whether I should move on (although by all means give it to me both barrels) as no one else knows the full story, but I'm happy to be there for her, but only if I'm not the only one who can't see I'm part of someone's twisted game.