Has anyone found anything that helps an Alzheimer's patient that yells and screams?

Teepa Snow has a lot of great videos teaching how to handle difficult situations. Try watching some of those on YouTube.

The filters come off, the soul acts from the subconscious, they are losing control...some seem possessed...it's hard to watch, I know.
Unfortunately I have watched many come through dad's memory care facility and no two cases are alike...a primary dr (tests) and psych dr (finding correct meds) should work together to find out what's happening w your loved one, and how to best serve him/her.
Tell them you would like to be involved in this process, and know up front, this might require some trial and error (so the one is not a zombie, alert during the day, and rests at night, etc)

I am the farthest advocate of drugs, yet Depakote was used as a mood stabilizer for my dad. This helped him balance out almost immediately...

Care for yourself...you will get through this and adjust to the new normals. This is the hard part, getting one stabilized, just do your best, and take care of yourself, too!

Yes, the Positive Approach to Caregiving! Teepa's Gems - find out by assessing which gem (stage) the above family member possibly is currently by reading her Gem Chart then intercede by trying the suggested methods. Remembering that the patients fluctuate even hour by hour so what may work one time may not be affective the next time. Do not assume it's the disease until all underlying issues are ruled out such as uti or some source of pain that they can't communicate themselves. Being kind back to the patient reassures and getting down to their level making eye to eye contact, speaking clearly and without anger. They will likely mimic back the attitude of the caregiver. Be sure no abuse is taking place. Etc.

Ibeenscammed, every dementia patient is different. The old saying is "if you meet one person with dementia, you have met one person with dementia". My mom is currently on Seroquel and Ativan. Without these drugs she would need to be restrained. She was becoming increasingly physically aggressive and no amount of diversion worked. The meds were started at a low dose and gradually increased until she became manageable. She is currently on an amount that I consider to be pretty high, but she has not suffered any bad effects and is calm most of the time. I am not disputing that bad drug reactions can and do occur, but sometimes drugs are blamed when it is actually the illness or simply old age that causes the death. I know that my mother is better off on these drugs than she would be restrained to a bed or chair. We all need to do what we feel is best for our loved ones and don't need others to make us feel guilty for the decisions we make.

What is the good old fashioned one two?

When my mom was given a calming drug that was said to have some side effects with the heart [she has no issues with hers] I said that she was already 5 years older than her mother & 18 years older than her dad when they died so I figured her happiness/contentment now is more important than a possible down the road issue

When someone goes on a drug & dies soon after, it is not always the drug that caused death but the reason they took it in the first place! - we all have to all die at sometime but it is the quality of life they lead that makes difference -

When I was in high school the dr told Grannie that she should stop drinking tea which she loved - mom said something about trying to get her to quit but I said then that I'd rather she lived 6 months happy than 9 month miserable - I still believe that

The yelling & screaming is a stage & will quiet down when they move onto next stage - check that there is no physical reason first as above writers have said - FYI there is no right or wrong with this caregiving just do your best & try to do as you believe your dad would wish - good luck

The best way to handle this type of problem is to talk to the person's doctor and have them prescribe a good sedative like Saroquel, or you could give them the good old fashioned one two, I'm sure many people have handled this kind of situation in that very way when all else has failed, and I don't blame them if it comes down to this 

For people who have very challenging behavior, I have found that the primary prefers that they consult with a psychiatrist, preferably, a geriatric psychiatrist. To me, they may be more equipped to order the most appropriate medication. (I realize that some Primary physicians do order meds for depression and anxiety in those with dementia, however, if the behavior is very extreme, I'd want closer look from a psychiatrist.)

I was part of the behavior team at the nursing home when I started training to be a NHA. We had a gentleman who was constantly screaming, moaning, and creating outbursts. What we did was give him puzzles to do (word finds, crosswords, sodoku, etc...). What we found was he was bored and our main purpose was to keep his mind busy. It ultimately worked for us. Now this will vary from resident to resident but you need to know what they used to like to do and what they can still do and keep their mind busy. Seroquel also helped but we found on the grand rounds if he was keeping his mind busy he needed less medication which was our goal to minimize the use of perscriptions.

Seroquel and similar drugs are extremely dangerous to give to elders. Yes I know it's tempting when an elder is loud. I personally cannot tolerate loud noises of any type. However, a friend of mine lost their mom to one of these drugs. They are really toxic to elders! My friend's family was able to sue. There have been multiple lawsuits regarding the use drugs. These lawsuits have been deliberately hidden from the public to avoid negative publicity. The dangers of these drugs have also been hidden. Why? These drugs make tons of money for the pharmaceutical companies. They can't afford to lose their billions.

These drugs should NEVER be given if the patient has any elements of Parkinson's whatsoever (including Lewy Body, or suspected Lewy Body). There has been a Black Box warning about this and it's often disregarded. Sometimes, Lewy Body is misdiagnosed as Alzheimer's, too. These drugs are given willy-nilly in nursing homes simply to silence patients. It's called "management." But really, it's elder abuse.

Researchers have used the Freedom of Information Act to dig up what has been hidden about these drugs, the hidden studies that show the dangers, and we can see what we should have been told all along.