Depression Support Group
Depression is a real and debilitating condition that is often misunderstood by family and friends. Its meaning can range from a prolonged period of sadness to an actual mental illness with specific symptoms. Find and share experiences with others who are going through the same struggles.
If this behavior (putting other friends before you) is consistent, I would say your friendship is not a priority for him. The question is do you want to make this "friendship" a priority of yours?
True friendships are supposed to be mutually reciprocal. If one party does not reciprocate, the relationship is not a friendship. It is a manipulative association in which one party is using the other.