My 80 y/o dad seems like he has a Dr Jeckyl/Mr Hyde personality and says he doesnt remember saying mean things to my mom. At other times, he says "well, she says mean things to me too!" I'm certain my mom never starts any arguments, however I can believe that once a heated argument is started (by dad), she just might say mean things too. Is this a symptom of dementia or depression. Mom always complains how "boring" her days are. He watches tv all day, never does anything else. She watches a little tv, does a little laundry, and naps. Any suggestions?