After claiming that jail and rehab were a life-changing wake-up call, why did Lindsay Lohan return to her old ways? Though she may have thrown away her last chance to salvage her career by failing two drug tests, which violated her probation, a friend said she’s only using drugs because she’s “bored.”

“When she first got out of rehab, she took it seriously. She didn’t want to do drugs or get back into that lifestyle,” a friend told Fox411.com. “But then, she had all these people around her who were doing drugs in front of her, and that’s when she slipped.”