Our sources say White left a suicide note addressed to Carrey which references their break up on Sept. 24. Cathriona tweeted on the 24th ... "Signing off Twitter,Very sad news.Why would a beautiful 28 year old woman with her whole life ahead of her wanna commit suicide? Was it over a man? The fact that killed herself 4 days after the break up suggests it played a very very big part.
I hope I have been a light to my nearest and dearest."
Law enforcement tells us they believe she died from an overdose of drugs - pills were next to her body. We're told 2 friends found Cathriona last night when they went to check on her. 53-year-old Carrey and White met in 2012, dated a few months and then split. They rekindled their relationship in May.