Adderall can indeed have hallucinogenic effects. It stimulates transmission of certain types of chemicals in your brain, and one of these chemicals is called "dopamine." ADHD is a so-called "dopamine-related disorder."
Schizophrenia also happens to be a "dopamine-related disorder" except that ADHD people are thought to have *too little* dopamine, whereas schizophrenics are thought to have *too much*.
If you (or your child) take too much Adderall, you can actually induce schizophrenic-like symptoms such as hallucinations or social withdrawl, because certain types of dopamine receptors in your brain are configured in such a way that makes you vulnerable to schizophrenic-like symptoms from too much dopamine. This is usually a good sign, because it likely means you are creative or have the potential to be so---you are more likely to "dream up" stuff, like new ideas and such. If you take too much Adderall, you are messing with a brain system that gives you the ability to "dream up" stuff, and that dreaming then becomes real to you in an unhealthy way.
Caffeine also increases dopamine levels, so adding it to Adderall is a very bad idea, and it also interacts with the heart in different, unhealthy ways.
My suggestion is to dramatically reduce your dose if you get to the stage where you are experiencing hallucinations. Cut it in half, but you should really do the following to help with any withdrawl effects: go out and buy some fish oil with a two-to-one ratio of EPA to DHA, making sure it has passed purity tests (for mercury, etc). This will provide a mild stimulating and focusing effect for your child, increasing dopamine a bit, and will also calm areas in their brain responsible for anger. Take the fish oil on the first morning that you cut the dose in half. Take the fish oil first, followed by the Adderall. For the fish oil, make sure you are not taking any blood thinners, are not alergic to iodine, and are not anticipating surgery. Fish oil may also mildly increase asthmatic symptoms. This is not hodge podge, there are some ninety thousand peer-reviewed research articles on the benefits of the eicosanoids found in fish oil, and I also happen to take it myself. Monitor stress levels and increase fish oil by your judgment to counteract withdrawl symptoms and stress levels. Children should take a fish oil "for kids", which comes at a lower dose.
If you want to get off the Adderall completely, you should still switch to a high EPA ratio fish oil the next dosing period, but you should also add the supplement "PS" to your routine. PS helps with the "working memory" problems commonly found in ADHD. Its full name is "Phosphatidylserine". You can find PS at most Walgreens stores. But take note: you should not take this with Adderall or other stimulants. A working memory problem has two qualifications: (1) when you're attentive you forget right away what you attended to. (2) You do things like forget where your keys are, have trouble remembering names, or have problems holding thoughts in your head for very long. See a licensed neuropsychologist for evaluation on working memory or other cognitive aspects of ADHD.
Don't take any of the other "natural" hodgepodge blends of gobbeldy gook they sell for ADHD on the internet. The high levels of tyrosine found in these products will likely cause depression in many, and messing with amino acids (like tyrosine) is generally not the best thing to do, especially with children.
And the moral of the story? Never blindly trust your psychiatrist. Also, be sure to get annual physicals, espeically for children. Just to be safe.
-A grad student in Neuroscience / Biological Psychology....with ADHD...
P.S. Check out my website as it develops:
www.noBSpsych.com
The information I wrote here will be saved and compiled with other things I've written / will write on the subject. Meanwhile, check out Dr. Amen's ADD book for some good brain-based information.