Dementia or depression?
I'm in my early 40s. My great-grandmother had some kind of dementia. I'm told she was confused, kept accidentally starting fires, things like that. Her daughter, my grandmother, also showed signs of it, asking the same questions repeatedly and so forth, but she was an alcoholic so maybe that was part of her problem. I don't know if it would have gotten worse because she died in her late 50s. My grandmother's sister, however, had serious dementia - completely unable to recognize anyone or care for herself before she died (in her 60s).
In recent years my mother (early 60s) has started to act like her mother did, needing simple things repeated to her many times before she understands them, but she isn't worried about it.
Now I'm getting worried about myself because I'm becoming confused a lot for no apparent reason. For instance, I went shopping and when the checkout person told me how much I owed, I became confused about how much money to give her. It wasn't that I couldn't make change (of course I know how to do that), but that I couldn't understand the amount she was asking for. I couldn't get my brain to make sense of what she was saying so I just gave her a lot of money and let her figure it out. This is unlike me.
Today I looked at a picture of a close relative and recognized him, then doubted myself and wondered if it was really him. Of course it was, but I continued to doubt myself. I know these are minor incidents, but this kind of thing is happening to me all the time. I am having trouble with my work because I get confused over simple things that I know well. And I can't seem to snap out of these episodes of confusion like I should.
I know I can't be diagnosed on a message board, but I wonder if someone can tell me whether it's possible my symptoms are caused by depression, since I have been very depressed this year, or if I am right to worry about early dementia, given my mother's family history. If it matters, I don't smoke or drink at all, and my nutrition is excellent. Thank you for any replies.