Happy Birthday to Me (1981), directed by J. Lee Thompson, stars Melissa Sue Anderson as a prep school student experiencing memory lapses while a series of murders targets members of her social circle. Co-starring Glenn Ford, the film blends psychological mystery elements with early-1980s slasher conventions set within an elite academic environment. The Canadian production became part of the post-Halloween cycle of mystery-driven slasher films.

Powerhouse films

Popular high school senior Virginia Wainwright (Melissa Sue Anderson) survives a freak accident, but suffers from memory loss and traumatic blackouts. As she attempts to resume a normal life, something terrible is happening - her friends are being ruthlessly murdered one by one. But will she be the next victim or is she the killer?

Director J. Lee Thompson's classic shocker was made during the period before the horror genre drenched itself in irony and self-reflexivity, and instead revels in the effective staging of the terrifying set-pieces which drive it towards its climax.

Från IMDB:
At the snobby Crawford Academy, Virginia's group of friends start to go missing years after horrible events that happened to her as a child around her birthday.