You may want to get your doctor to write your ex husband a letter explaining the issue and especially explaining the dangers of having a child go off and on this type of medication. Instead of letting the emotion (or perceived emotion) get a hold of the situation, let a third party communicate the facts--especially the dangers.

File a petition to alter the terms of your custody arrangement. I'm assuming you have a court-ordered or court-sanctioned custody agreement following your divorce? You can always go back to the Judge to change the terms of the agreement. File a petition and lay out the reasons you either need to have him more often or your ex can only have supervised visits, or however you feel you can best remedy the situation (YOU, not your ex, cause clearly you can't count on him to follow direction). Include a note or letter from your doctor stating that your son has to take the medication, how frequently, and why he cannot be allowed to self-administer. I can't guarantee it will work, but at least it's another option.

It is a form of negligence called medical negligence, I believe, for a parent to not give meds. I’m shocked that DCFS won’t do anything! CPS? My ex is the same but my child is only on meds when she is sick. And I have a hard time proving that he’s not giving her the meds. He’s smart enough to pour some out. I’m sorry and wish you the best of luck. Do you have to have an attorney? Could you fight the petition yourself? Or would you qualify for Legal Aid? Best of luck! I feel your pain to an extent.

Take video of your son with you on his medicine & record when he gets home and exactly how different he is. Remember unfortunately with courts it's what you can prove not what you say

Do you have older children who are there with him…who MAYBE take on that responsibility? If not, what about an in-law, family friend, neighbor? As WE ALL KNOW, the CONSISTENCY is VERY important