Can you still get PPD even while on antidepressants?

This is probably a stupid question. I’m just super lost. I was on antidepressants before getting pregnant and now I’m back on them. My daughter is 2.5m old and I’m just wondering if you can still show signs of PPD while on an antidepressant. Like maybe my doctor needs to up my dose? I just feel “depressed” such as lethargic, I don’t want to hold my baby as much, I’m dissociating a lot, and I’m just overall no longer happy like I was a few weeks ago. I dislike having to go anywhere now whereas I used to want to go out every day and do stuff. Also, is it normal to not be able to remember things? My memory is so shit since giving birth it’s caused me to be so frustrated because I can’t remember anything and I have to write everything down now or put it on my phone. I’m a first time mom so I’m just trying to get by. Thanks ladies.