Maudikie.
Everyone has their ups and downs in life. The difference between a "fed up£ depression and bi-polar depression is a much greater swing between the feelings. The ups and downs of clinical depression (bi-polar) are directed by the brain structure, and are an illness, The fed up derpession is a simple reaction to outside circumstances which pass, or which the person has he ability to adjust to. Grief usually passes with time, and if it is an inevitable event which has caused the grief, this can be accepted with time. It usually brings synmpathy and care from family and friends.who can be a great comfort.
Clinical depression on the other hand is a medical condition which can be relieved by medical treatment, and added support from friends or professionals.
Rehabilitaation can help alongside medical care.
Sometimes it is difficult for people to let go of bad experience or loss, and ability to "move on" is particularly difficult.