Don, sorry you're having trouble recovering from the depression.  When it reoccurs, does the doctor try a different medication each time?  I know this can happen, people being resistant to medication.  And now I must ask you, are you in therapy?  If you have some underlying problems that are the root of the depression, you could probably benefit from therapy where you can learn some coping skills and maybe different ways of thinking about yourself.  The meds can only help so much - if nothing in your life changes, the problems are still there.

Also, feel free to write here any time - there are always people here willing to listen who may have been through what you are going through.  We help each other by sharing our experiences.  I wish you the best, please take care.