Amanda Bynes -- Stable, Lucid and Off Meds

Amanda Bynes is OUT of her manic state ... acting completely "normal" and her family thinks it's nothing short of "mind blowing."

Sources familiar with the situation tell TMZ ... Amanda is off all meds, including Adderall, which caused her to get a DUI.

When you speak with Amanda there is no way you would know she's been diagnosed with schizophrenia and bipolarity. She is completely lucid.

We're told things have stabilized so much, her parents have given her limited access again to bank accounts. She spends her time reading, doing yoga, meditation and pilates ... all stress reducers which doctors say are important for these mental disorders.

We're also told Amanda's recent trip to USC -- where she'd like to enroll as a psych major -- was all planned by her.

Here's the rub. Doctors have told Amanda's family, people with such mental illnesses sometimes rebound and they can be ok for months, only to relapse again.