Applying with disadvantaged status will make up for some gaps in your background, including sub-par ECs, but only to a point. You definitely qualify as disadvantaged, but you'll need to explain the conditions that qualify you in an objective way on the application.
Don't expect an URM advantage. URM students are accepted with lower stats to fill the diversity requirements of the accrediting body; disadvantaged students are not. You'll still get by with fewer ECs, but don't expect much leniency on GPA and MCAT requirements. Applying as disadvantaged can only hurt you if you aren't sincere about your status or use it as an excuse for underachievement. If you explain yourself succinctly, however, it will play to your advantage in the application process.
First, I'm so sorry to hear about the mental health issues facing your family. I bow down at the feet of anyone who cares for loved ones facing mental illness (especially PTSD), and/or are navigating the "system" for psychiatric care in this country.How does applying as disadvantaged affect one's application? Will it hinder a school from accepting me, or do they generally try and assist disadvantaged students with getting in? How does disadvantaged compare to minority in terms of acceptance? My mother's side of the family is Tunisian.
Also, should I apply as disadvantaged? My parents are divorced and neither have a job. My dad was diagnosed with PTSD stemming from his time in the navy and he lives off disability. My mom, whose dependent I always was, was also always unemployed. I have three siblings who are all severely mentally handicapped and the amount of time that she had to put into their care kept her from a job. She basically ran the house off social security for my siblings, so our income was typically under $20k/year for five people. We always received food stamps on top of the SS and I did contribute to household funds before 18. I was approved for FAP, which is making my app possible, which is really great.
Thanks for any advice!