I've suffered with depression for many years on and off.
I tried CBT and it really helped. After that I felt good for quite a while and I thought great I'm cured of depression. Then I eventually began to feel bad again and this time I felt worse than ever as I was so aware of what was going on and I was so dissapointed as I thought I had been cured. I was angry at myself for letting myself fell low again.
Anyway, with the help of my T I came to realise that my depression can't be cured. I just have to learn to take good care of myself and use the techniques that I've learnt to help myself cope when the depression does come back.
So, for myself, no I don't think my depression can be cured but it also doesn't mean I will be continually depressed. My T says some people can go for years without feeling depressed. I just think the important thing is being able to cope when it does.