Great question, but such an unfortunate situation for your daughter. Here is my impression: (and I give this with the knowledge that having active hallucinations in an eight year old is REMARKABLY uncommon)
The main neurotransmitter that is affected by the Concerta is called dopamine. ADHD is a general lack of Dopamine, so Concerta kick-starts the brain to make more. I have seen it happen (although this is somewhat rare as well) that a kiddo on an ADHD stimulant can actually have the dopamine levels overshoot the mark and will wind up creating some psychotic features (hallucinations, generally).
So here is my advice: talk to the prescribing doc and ask if your daughter can get all the way detoxed from the Concerta before her ultimate evaluation. As I mentioned, florid psychosis in eight year olds is almost unheard of - especially if there is not a family history of psychotic disorders (NOT impossible, but rarer than the side effect of stimulant meds, in my experience). That is the only way we can accurately assess what is driving the hallucinations. I assume they are a new symptom, by the way.
In any event, the medication prescribed to her is appropriate if she is hallucinating, but we really need to know if the symptoms are organic or if they have been created by the medication.
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