People don't experience things in the same way. Each person is different. People may experience severe depression at some point in their life but it doesn't mean they will have it continously for their entire life. Some people may claim to have it for long time and that it will last, but others have had it for some duration of time but managed to overcome it, to see the light, feel freer and change positively. That is a really pessimistic picture if you believe that It will continue to be there for whole life- its not like a physical illness like diabetes which has to managed each day permanently. It is stress related largely.At the end of the day the aim is to help you as a person, not the depression. That won't work if you think that ur powerless to depression.We aren't the depression. It isn't part of our true self. We can learn to be more in control of our own selves, be our own best guide, overcome things manage factors better that could trigger depressive episodes,to live more freely happily without feeling vulnerable to getting depression again and again. Even make depression your friend rather than your enemy so you can liberate yourself . I believe it has hidden underlying messages that we need to listen to and take on board. For me anyway it has.