If you know that your future happiness relies on 6billion people dying first, it is a little bit difficult to remain joyful and happy. One represses the knowledge and tries to just get on with being a good christian. The negative feelings emerge in dreams and times of stress. Rather than deal with the source many feel that they are depressed without real reason and so begin to take medicine. Quite a lot of jws spend a fortune on alternative medicine first. They try to cheer each other up by saying that the depression is a sign of coping with the last days and it proves we are near the end.
In my congregation we had many sisters suffering with depression and on medication, the brothers who were ill were avoided. I suffered for years myself before I dealt with the real causes. Many who become jws are from abusive backgrounds or emotionally damaged in some way, they are almost programmed to become ill at some point.