MARIAH CAREY was so heartbroken after reading reports of WHITNEY HOUSTON's alleged descent into drug addiction, she has invited the fallen star to duet with her on her next album.

Carey is keeping a close eye on the troubled singer - and is determined to help Houston beat her demons and make a glorious comeback. She says, "My heart goes out to her, she's such an immense talent. I'm right there for her." (ZJS/WNTRE/SC)