When a star gains just a few pounds, it might be a quick "water cooler" topic. But when Lindsay Lohan's gains weight, the rumor mill goes crazy.

The "Mean Girls" star, who is reportedly acting up during her current rehab stay, has added on five pounds to her slender frame, according to Contact Music. The cause, you ask? 

Apparently, Lilo's minumum weight gain is because of her withdrawal from Adderall while staying at the Betty Ford Center in California. She was mad, reportedly, after doctors ordered her to stop taking the drug, which she said treats her attention deficit hyperactivity disorder or ADHD though many use it for its metabolism-boosting, weight-loss effects. Lohan has been working out but not enough to combat the gain, according to a source at the center.

"She has been exercising, but she just doesn't have enough energy because she is no longer taking Adderall, which is a psychostimulant medication that contains amphetamine," the sources said to the Inquistir. And Lohan maintains that she never used the drug to slave off the LBs, but instead to keep herself sane and still. 

But we know that the weight gain is not her biggest issue. The star still has 80 days of rehab left, and we hope by some miracle that she will get it together.  

What do you think?