My boyfriend is depressed

I love my boyfriend very much and we have been together for 4 years. I know depression has been something he has battled with on and off throughout his life and even when we first started dating, he told me about his depressive thoughts and how he was depressed before we got together. After we fell in love he was happy and he used to say that he thinks his depression is gone for good because of how good it felt to be together. He's felt low since then, but it always seemed like the sort of thing everyone goes though, just bad days and then move on. But a few months ago he started becoming isolated and withdrawn and I know now that he is definitely depressed. He hardly ever talks now and he's losing weight and he doesn't eat properly. Nothing changed in his life, like there wasn't any traumatic experience that happened recently so I have no idea what triggered this. I have tried to talk to him about his childhood, like maybe something bad happened to him when he was growing up but he always says he doesn't want to talk about it because he doesn't have any bad memories.

I am really worried about him. I'm scared that he might have repressed memories of something that is causing this depression in him, he has always said he doesn't really know why he gets depressed, only that when he is depressed he can't believe in anything good. I would really appreciate any advice. Should I try to talk him into seeing a therapist? Can people have repressed memories that make them depressed?

As someone suffering from depression myself I have some idea how it might feel for you being in a relationship with someone suffering from it.
There are no easy solutions for depression. One of the most frustrating things about depression (and one of the things that can trigger a spiral into deeper depression) is that we cant figure out why we feel so bad. The initial reason we feel bad can be due to many things like childhood experiences or our genes, but most probably a mixture of both. I read a recent article that said that the influence of genes compared with environmental factors on your "happiness" is actually about 50:50. This thought is both upsetting and a relief. Its upsetting because it would indicate that if I have depressive genes, there is only so much i can do about it but i will ultimately always be partly depressed. It is a relief because it kind of takes some of the pressure of feeling like its my own fault that I am depressed. This comes back to that downward spiral. We feel bad and dont know why and then part of us usually blames ourselves and says "come on you sook get over it" and "your such a sulking sorry sack feeling sorry for yourself" and so we put ourselves down which in turn adds to our deflated self image and at the same times makes us less resilient to the effects of depression. And so realising that it is not our own fault, that our negative feeling are something we are born with can ironically really help. Who knows anyway, I think maybe also depression is just a result of people being born with a mindset and perception that is out of sink with the main trends of current societies social conscious. We live in such an all encompassing all pervasive social world these days that if we have some fundamentally different values and attitudes to the mainstream it can be a burden. However this is only part of the explanation and ultimately it is important for people to realise they hold the key to their own happiness. But for a depressive person, this is easier said than done. One thing I can suggest, that I think is a healing therapy for so many afflictions is - the power of helping and doing good/charitable things for others. This is not just a 'goody two shoes wives tale'. The positive mental benefits of helping others has been scientifically demonstrated in many studies. And hey, deep down we know it makes sense anyway. Try and get your boyfriend to help in a charity event with you or simply just get him to buy some presents for family members or both. I hope this helps.