Pharmacist Cynthia Haines was introduced in the summer of 1981 while David Stewart was in her hometown of Flat Rock suffering from amnesia. David was seeing a psychiatrist, Dr. Matt Butler. and was now going under the assumed name of Donald Saunders. Donald quickly fell in love with the very attractive Cynthia Haines. Cynthia's teenage daughter, Karen, was thrilled to have a new father figure. Unfortunately for Cynthia, John Dixon recognized David and alerted his daughter, Dee, to his whereabouts.. Dee ran to her father and hugged him, only he didn't know who she was. Then, he keeled over -- he'd had a heart attack from the shock. David didn't recognize his wife, Ellen, either and asked for Cynthia. Still suffering from amnesia, David ironically came to believe that John was the only one he could trust. David agreed to be injected with sodium amatol, a type of truth serum, and his memory returned.. Ellen was ecstatic that her husband was regaining his memory, but Cynthia was heartbroken.

Throughout the rest of 1981, Cynthia continued to have to face the fact that her new husband, Donald Saunders, was gradually drifting away from her and becoming re-involved with his life as Dr. David Stewart. Her daughter, Karen, was also not too happy and suggested to her mother that she live in Oakdale to keep an eye on David and the Stewart's for her mother. Despite Cynthia’s reluctance, she agreed to Karen’s proposal. Instead of helping the situation though, Karen ended up having a brief fling with the young Eric Hollister. Eric, a construction worker and aspiring doctor, had been found by Karen, on one of her first days in Oakdale, unconscious in Fashions, Ltd. Eric had been given PCP by accident, but after he was taken to Memorial Hospital, many assumed that Eric was drug addict. One of those was Cynthia and she was not too happy to learn, from David, that Karen decided to take up with the man. It would be learned later that Eric did not take the PCP intentionally and Karen decided to call it off with him when she realized the depth of his feelings for his true love, Hayley Wilson. The next man that Karen took up with, though, would make Cynthia even more upset. That man was Dr. Jeff Ward who was pining away for David and Ellen’s oldest daughter, Annie.

At this time, David still missed Cynthia who bought a pharmacy in Oakdale as a way of staying in touch with David. Confused over his love for two women, David sought advice from his psychiatrist, Matt Butler. In session, David portrayed Ellen as caring and compassionate, but Cynthia made him feel alive. David tried in vain to revive his old passion for Ellen, who was sure David was still in love with Cynthia. After begging Ellen not to divorce him just yet, David took a leave of absence from the hospital and went to Florida to think. Cynthia was encouraged that there might be hope for them. Meanwhile, Ellen moved into an apartment and tried to adjust to single life and even began dating a man named Ben Forrester. When David returned, he and Ellen agreed to divorce. However, David still couldn't tell Cynthia what the future would hold. Meanwhile, Ben Forrest became so attracted to Ellen that he started contemplating proposing marriage, but a strong bond still existed between Ellen and David. Seeing Ellen with Ben upset David, and realizing he was still in love with her, he broke it off with Cynthia who later returned to Flat Rock.