Although not likely to be references nor they are particularly the same, for the ones who saw 'Save Me', a drama that had Seo Ye Ji's as main lead, there are three subtle similarities in 'Psycho But It's Okay' that reminded me of 'Save Me'.
First one is on Episode 3 when Go Moon Young has her first nightmare. Although she wasn't the one that said it, her mother said 'Save Me' over and over again which is a line that Seo Ye Ji's character says a lot in 'Save Me'.
The second one is on Episode 5 when Go Moon Young and Nam Joo Ri fight. In 'Save Me' Im Sang Mi throws the box of milk in the canteen whereas in 'Psycho But It's Okay' Go Moon Young hesitates to hit Nam Joo Ri with it.
Third and last one, right after Im Sang Mi throws the box of milk she tells him to apologise. This apology request also happens on Episode 2 when Go Moon Young asks the man to apologise to Moon Kang Tae.
In spite of the fact that these words are quite frequent in dramas Im Sang Mi's character was really well known for these scenes which makes it intriguing nonetheless.
I'm sure these are mere coincidences but I'd like to think of it on a deeper level which can make the drama even more interesting for the ones who watched 'Save Me'! :)