Lindsay Lohan just wrapped up rehab, and sources say she's doing better than ever. But when it comes to what she was actually in rehab for, that's up for debate.

Lilo, who's been in rehab for booze multiple times, initially refused to enter treatment this time around if she couldn't take Adderall with her, and now someone else is insisting that the ADHD drug was her real problem: her 'Canyons' director Paul Schrader.

"I honestly think it's the Adderall," Schrader told the L.A. Times' Movies Now (via Radar Online). "It's the most abused drug for young girls in the country. It kills your appetite, allows you to stay up and hyper-concentrate."

Schrader insists that Lohan "is not an alcoholic," but as a matter of fact is quite the opposite: He swears she has a low alcohol tolerance. "She is a cheap drunk," Schrader said. "A couple of glasses of wine and she shows the effects."

The director admitted that he hired Lohan specifically for the drama that she'd bring to the set with James Deen and writer Bret Easton Ellis, something about which he later complained to whoever would listen.

"To be honest, it’s something we created. We stirred the pot, simply with the casting of Lindsay and James," Schrader confessed. "Lindsay brings with her, her drama, and then Bret, he has a very promiscuous Twitter finger, and he can always [be] relied upon to upset somebody with some tweet."

He added, "Lindsay does live in a world of created drama; she seems to live in a cone of crisis. A lot of it is unnecessary," he said. "You want to say to Lindsay, 'Why are we in this emotional upheaval?'"

"More than once I said to her, 'It really must be hard to be you.'"

Yeah, it really must be hard to be Lohan. Especially when her directors sell her out about her addictions.