We also shared endless conversations about love and relationships. Friends are supposed to be there for each other through the good times and bad.
I also realised I could no longer sustain a totally one-sided friendship. It may sound callous, but I had to extricate myself. I toyed with having a blunt conversation with her but I'd tried so often there seemed no point.
Very deliberately I stopped returning Deborah's phone calls quite so regularly. So finally, just after New Year 2003, I sent Deborah an email explaining that I could no longer be her friend. I didn't want to hurt her but I knew I owed it our friendship to be honest.
I'd put the phone down after two hours, completely drained. Nick would sigh every time the phone rang and I disappeared for an hour or two, only to re-emerge, emotionally shattered.
Even when Nick suggested I might be taking the friendship too far, I didn't listen. One day he told me: 'This has gone beyond friendship. And worst of all, you are making no difference because she won't listen.' I knew Nick was right.
Finally, I explained that I would always be there for her but I didn't want to hear from her again until she had got professional help. But - like a marriage that goes bad - I can now see it in two parts. Through my work, I've met many other women who have been through similar traumas.
There were the early days when we were equals and had glorious fun. One was devastated when her best friend met another woman, who gradually displaced her.We knew each other inside out and I was convinced we'd be friends forever.So that's why, looking back, I felt the most uncomfortable sensation - a mixture of huge happiness and a deep ache of loss. Almost seven years ago, I ended our friendship after I realised she had become way too needy.Another woman was distraught because every time her best friend met a new man, she dropped her.She knew she was being badly treated but she felt so loyal to her friend, she found it hard to let go.But, with no partner, I was particularly open to finding a new friend to share things with. With two children I adored, I could understand how loudly her biological clock was ticking.