The `Firework` hitmaker says the sudden death of her spouse`s friend Amy Winehouse on Saturday (23.07.11) has given her more of an appreciation for how the 36-year-old funnyman has managed to stay sober for several years after being treated for heroin addiction.

Speaking about Amy, Katy told US TV show `Good Morning America`: "My heart felt really sad. My husband, who has been clean and sober for almost nine years, you know, I see him working a programme and working on himself every single day. And I see how much work it takes to be clean and sober when you have, you know, addiction on your hands.

"It gave me a real a gratefulness for my husband, who got clean when he was 27. I feel really sad and I just hope she finds peace."

Following the death of 27-year-old Amy - whose passing is believed to have been related to drinking and drug taking - Russell penned a moving blog in which he paid tribute to his friend, calling her a "f***ing genius" and warned against the dangers of addiction.

He wrote: "When you love someone who suffers from the disease of addiction you await the phone call. There will be a phone call.

"We all know drunks and junkies and they all need help and the help is out there. All they have to do is pick up the phone and make the call. Or not. Either way, there will be a phone call.

"We have lost a beautiful and talented woman to this disease."
sections: Celebrities