I heard that if you have an underlying mental disorder such as schizofrenia and you take dex for your a.d.d. that it will come into the forefront and cause havok. Anyone heard anything on this?

I do believe that ALL stimulant meds used to treat ADD/ADHD are contra-indicated if you suffer from bipolar disorder, schizophrenia, and other such disorders. See your doctor, or speak with your pharmacist for additional details.

Agree with BIG - you always need to fully disclose other medical conditions & any other drugs (legal or illicit) you are taking, even disclose any vitamins or herbal remedies. All of these can have an impact on what meds you should or can take. Your doctor needs to be fully informed for your own safety. Even if you have not been diagnosed with another condition but think you might have it let the doctor know. It is better to be safe than sorry. :)

Better safe then sorry is right! when my a.d.d specialist asked me about my past and present drug use i told him everything. I totally agree that a patient should disclose all drug information to doctors.