Some characteristics of depression in the aged were elucidated. Compared with the previous thoughts, much more attention was given to the biological aspects of depression. However, we have to face up to and solve a variety of enigmas about depression in the aged people. They are:locations and underlying mechanisms in the cerebrum responsible for depression;relationship of senile depression to the presenile one;possible difference(s) between depression with and without psychotic features;possible neurotransmitter differences between senile and presenile depressions. New insights into these areas could bring some lights in the under standing and treatment of depresseion in the aged.