Nicole Richie is back on drugs!

During her younger years, Nicole Richie was hooked on heroin.  It looks like she is resorting back to old ways -- sort of... this time she's evidently hooked on pills. 

According to a source quoted by InTouch Weekly, Richie is not just taking pain killers.  She's also taking Adderall, a drug normally perscribed to those diagnosed with Attention Deficit Hyperactivity Disorder.

Insiders say Nicole has been using Adderall - a prescription drug normally used to treat Attention Deficit Hyperactivity Disorder and is a powerful appetite suppressant.

"She loves Adderall because she stays awake, and it makes her not want to eat," says a close pal. "And she takes it even more when she's filming."

Although her rep denies that she uses the drug, a pal says Nicole's actually increased her dosage: "She's taking more and more lately."

Richie also confessed to smoking weed when pulled over last year for driving the wrong way on the freeway.

Nicole is currently shooting the latest season of her hit reality show The Simple Life with co-star and once again best friend Paris Hilton.

Well, one thing we have learned from Anna Nicole Smith's death is that celebs can get a note for whatever they want in Hollywood.