Lindsay Lohan -- Adderall Free ... For Now

Lindsay Lohan has waved the white flag in her battle for Adderall ….. TMZ has learned.

Lilo has put up a tough fight to keep the Adderall train rolling in rehab. First she threatened to boycott rehab unless she got the Rx drug, then she pitched a fit at Betty Ford when they took it away, but sources close to her tell us she's finally ok living Adderall-free in the new facility.

As for why she's off the drug ...here's Lindsay's story. She's telling friends she felt it was essential for ADHD -- something she was diagnosed with when she was very young. FYI -- LiLo's new docs think it was a bogus diagnosis.

Adderall has become a popular drug with young actresses for weight control -- a popular, addictive and highly-abused drug. As for the real reason she felt the need to take it ... who knows.