i've been depressed my entire life and my dental hygiene used to be atrocious as a kid. these days, in my late 20s, i typically brush once a day in the morning and mouthwash before bed because the day takes a lot out of me energy wise and brushing my teeth ends up feeling like a monumental task. i go to the dentist every 3 to 4 months so more than the average person, but my insurance covers it. i use an electric toothbrush. i've only had one cavity and have all of my teeth including my wisdom teeth because they're not damaged and don't have cavities.
Many people fail to think about the depression and lack of brushing. I too am in the same boat. Turns out my meds are even making my teeth soft no matter what i do..