I would like to offer some extra info .
Since you are looking for OTC . Both NAC and SACROSINE have a lot of great research when it comes to schezophrenia. It seems to work for some but not others.also new research into TMG (betaine glycine) is also interesting
There is also a new drug on the horizon that doesn't work on the dopamine receptors and has much less side effects than what's currently
SEP-363856 helps treat negative symptoms of schizophrenia such as Inability to experience pleasure, Lack of interest in relationships, Lack of motivation. 5HT1A and taar1 agonist
https://www.medscape.com/viewarticle/913348
MIN-101 - a ~20% BDNF increase. Treats negative symptoms of schizophrenia. 5HT2A and sigma2 receptor antagonist.
Min-101 has a targeted release of 2021/2022. After they have completed their 12 week phase 3 trial, they will do a 36 week phase 4 trial. SEP, should also be available sometime in those two years as well.
Hope your daughter finds peace