When ABC decided to make a TV movie out of Last Wish, journalist Betty Rollin's account of how she assisted in the suicide of her terminally ill mother, the network had no idea that Derek Humphry's how-to manual Final Exit, with an introduction by Rollin, would become a best-seller and turn the topic of planned suicide into front-page news. Now that the film, starring Patty Duke as Rollin and Maureen Stapleton as her mother, Ida, is done, executive producer Joan Barnett is monitoring the public debate with some anxiety. ''Obviously, it's a very mixed bag,'' she says. ''You make a film about the subject, and you want people to watch it. But if people think they're going to get a recipe for suicide, they're not.''
Rollin's book deals explicitly with the mechanics as well as the emotions of suicide, but the film will not identify the drug she obtained for her mother. ''We had to deal with great caution in our film,'' says Barnett, adding, ''This is not a clinical piece. Ours is a story about the love between a mother and a daughter.'' That's the approach ABC may take with potential advertisers, who could be skittish about the controversy. Last Wish is set to air in January.