Maybe the dad has ADD.
I didn't read you post well in terms of where you are with court. I do know courts would hear your case better if you had documentation/letter from the childs doctor(psychiatrist) as to 1. found a medication thats working 2. the importance of it being taken daily 3. possible consequences if its not taken daily - scientifically what are the symptoms.
Then your own statement outlining the behaviors you see upon return from dads, your understanding she's not getting her meds, for about how long this pattern has been going on.
I would think your request would be for the court to order dad to be responsible for making sure child takes medication as prescribed.