Is anger at an elderly age a type of depression? I have a close relative who is an extremely talented writer and brilliant intellect. Suddenly with old age he became hostile with his family members, having no desire to talk with them at all. He was an excellent father and husband, too. When talking with other people he doesn't show any insanity at all. His mind is as brilliant as it was before. The family is in despair. Could it be a type of depression? If not, what it could be?
Anger developed at any age is anger. It could be a sign of many things, from frustration with age-related decline to longstanding lack of impulse control to a kind of general irritability that is associated with both depression and mild forms of mania. Sometimes anger results from brain damage such as might occur from a stroke. The irascibility that is sometimes seen in older people probably has many contributing factors—losing powers or becoming dependent on others could do it for some. An important one may be general decline in energy level; it takes a certain amount of psychic energy to keep one's emotions in check, and who better to let loose with than family members. However, that your relative seems hostile only with his family members suggests that something else is going on. Perhaps Dad is ashamed that he is not the excellent father he once was to his family; shame often manifests as anger. Perhaps something specific has occurred to sour the relationship. Do the family members talk to him in a childish or other demeaning way? Have they been holding discussions about the will or personal property without Dad's consent? Have they pushed him aside or left him out of discussions on matters in which he used to take part? Maybe nothing has happened but something or someone has planted the idea that his family is betraying him in some way. Perhaps he holds them responsible for some unpleasant event that happened years ago. The possibilities are almost endless. The important thing is that the air needs to be cleared. Why can't a trusted friend of the family be called upon as a mediator? The person would need to sit down with the family members and get information from them, and especially ask what was going on around the time the hostility started. Then the friend could sit down with Dad and ask why he seems to be so angry with them. Telling him that his family is hurting because of his behavior might be enough to stir his compassion and shift his behavior. Or the conversation could reveal a misunderstanding that needs to be openly discussed and cleared up. Get going. You don't have forever.