Case-history plot with a twist; Twelve Dreams; Play by James Lapine. Directed by Mr. Lapine.

Last year, playwright-director James Lapine's ''Table Settings'' spread a feast of laughter for local playgoers. The new Lapine drama at Public/Martinson Hall affords few such delights. ''Twelve Dreams'' is a melancholy excursion into the world of psychiatry and dream interpretation.

Case histories in the guise of theatrical works have become an all too familiar article in today's theater. Mr. Lapine may have added a slightly new twist with ''Twelve Dreams.'' In so doing, however, he makes psychiatry seem like the clouded crystal ball of medical practice. Perhaps that is what he intended. Since the time of the play is 1937, Emma's plight may contain a metaphorical allusion to western civilization's approaching crisis.

Staging, scenic inventions (by Heidi Landesman), and performance combine to create the mixture of actuality and fantasy the work demands. But there is little substance among the shadows.

According to a program note, ''Twelve Dreams,'' although entirely fictional, was inspired by a case study of Swiss psychiatrist Carl Jung's as recorded in ''Man and his Symbols.'' The plot centers around widowed New England psychiatrist Charles Hatrick (James Olson) and his little daughter Emma (Oliva Laurel Mates) who dreams the dreams summarized in the program notes. Emma's nightmares are interpreted as omens of self-destruction and the story has the self-fulfilling prophecy leading to the child's death after a short illness.

As the action alternates between the real and surreal, Mr. Lapine relates Emma's and her father's predicament to everyday associations and occurrences: Hatrick's relations with colleagues (Stefan Schnabel and Thomas Hulce) and a hysterical patient (Carole Shelley); Emma's playmate (Stacy Glick) and dancing teacher (Valerie Mahaffey); and the cousin-in-law (Marcell Rosenblatt) who keeps house and serves as Emma's surrogate mother. The children's scenes are particularly appealing as played by the young Misses Mates and Glick. Miss Shelley and Mr. Olson handle the play's more emotional encounters with convincing intensity. Allen Shawn has composed incidental mood music.