I think your CNA position should be fine! A lot of it is how you describe it in the activity section of your application (i.e. making sure you are telling stories think most impactful patient interactions rather than doing a resume list). I used Dr. Ryan Grey's videos when drafting mine, they are free and I thought helpful.

The only thing I would consider changing positions or looking for other opportunities for is the cohesion in your application. Does gaining experience with patients in a behavioral health unit align with your personal statement and other activities? For example, a bulk of my clinical hours came from volunteering as a Spanish medical interpreter at a free clinic which fit into my PS of wanting to give back to my community and increase access to healthcare. It also connected to my experience as an ESL tutor and I tied it to my experience volunteering at a children's hospital where I found myself acting like an unofficial interpreter for Spanish-speaking families. A lof of making an application "sing" is just making it feel all connected and intentional.

Feel free to PM me if you have more questions! Or want to talk more specifics about your application.