J, your Mom is crying out for help. You are aware of her Alzheimer's which alters her ability to use good judgement and make good decisions, yet you are allowing her to determine her medical care? You are aware of her depression and hear her cries. Yet you let your father and sister let it be about what they want and not about what Mom needs? You are here so I am sure you are doubting the path your family is taking... GOOD FOR YOU!
Depression is one of the side effects of Alzheimer's!! A large percentage of Alzheimer's patients are depressed at some point during the early/mid stages of the disease. Antidepressants do help. I was like your Father and sister in the beginning of my Mom's journey through Alzheimer's. Then I learned better. Mom finally went into a manic episode of depression, aggression, and combativeness which landed her in a Geriatric Behavioral Med Unit (Geriatric Psych Unit!). The kind psychiatrist explained to me that pain is pain, physical or emotional. If she had a pain in her stomach I would do something about. If she has emotional pain and I willing to just sit by and watch her pain? There is such a stigma in this country relative to mental illness and it bleeds over into Alzheimer's. Alzheimer's is not a mental illness but a brain disease. Yet the symptoms can be the same and the treatments are the same. In the end my Mom was on medication for bipolar, depression, and seizures. She went from manic to content. I left her on the medication for 4 years, until her death, and she remained content except the days she did not have her medication so I know they worked.
Rose is right, if you can not get Mom to the doctor then ask for in home care. Let the doctor know what is going on. There are now doctor that make house calls... find one. But somehow you do need to get Mom treated for this depression before she acts on her threats.... in the form of aggression towards herself or others. This is not something she is just going to get over.
In order to get Mom to the doctor, please do not discuss with her or ask her if she approves. She may or may not be processing what you are asking her. She may have old fears of doctors. She may understand enough to know that she is sick and fearful of what she will be told. Make the appointment, tell her you are going out, and end up at the doctor's office. Prewarn the office that she is uncooperative but she has to be seen because of depression. Hopefully her doctor is equipped to treat her emotional distress. Or, you may want to make an appointment with a geriatric behavioral management specialist or geriatric psychiatrist.
Some of these steps are difficult but it is a necessity. Your Mom is in emotional pain. It's not about Father or Sister... it's ALL ABOUT MOM and what she NEEDS. I have been there and seen the positive results when good emotional management is provided. It can make the difference of being able to keep Mom at home or placing her. Emotional distress will escalate....
Know I will keep you and your family in my thoughts and prayers... and if you have any more question or want to vent further.... please keep posting