Mrs. B. was convinced that the 'grooves in her fingers were smoother,' and that the double had taken her fingerprints. She was so concerned about the existence of another Mrs. B. that she required the constant presence of her driver's license to reassure herself that she was the real Mrs. B. In addition to her delusional belief, Mrs. B. reported that she had actually seen the other Mrs. B. She believed that the other Mrs. B. was also a patient in the unit who looked exactly like her facially but was heavier in the body. (Another, younger, patient, who was pregnant, was actually the person upon whom this illusion was superimposed.)"