Writing fiction can be hazardous to your mental health," says Diane Chamberlain of Alexandria.

And who should know better than Chamberlain, with two books (Private Relations and Lovers and Strangers, Jove paperbacks) already published and a two-book contract in hand -- all in the midst of counseling patients as a psychotherapist.

With romance-writer fame knocking at her door, Chamberlain is well on her way to creating her own angst: juggling the multiple personalities and demands of writer and therapist. "It's moving from fantasy to reality and back again . . . It's not always so simple to do," she says.

Especially if you develop close relationships with the fictional personalities in your novels. Chamberlain finds magazine photos of people who match her imaginary characters and posts them by her word processor. She throws parties for them in her mind, plays the music they like. "I have learned how to keep some emotional distance with my clients," she says, "but I haven't figured out how to do that with my characters."

Chamberlain often draws on her own experiences for plots. She explores agoraphobia -- an illness she once battled -- in Secret Lives, scheduled as a HarperCollins hardback release in February; among the characters is a woman who finds security by living most of her life in a cave in the Shenandoahs.

But Chamberlain says she draws a distinct line between the lives of her clients and the personalities of her characters. "It's more fun and less limiting to pull characters from my imagination rather than from real life. I don't ever want one of my clients to see themselves in one of my books."