Depressive disorder is a something that happens in the brain...the serotonin cells in the brain just are not enough to stay happy. So the person can be diagnosed with the disorder at any time. The people who live or know someone with it can have a hard time dealing with the person. It is not the person's fault that their body can't produce the serotonin that is need in the body.
I was diagnosed with depressive disorder sometime back, can you help me out doctor?