Placebo Effect is an original novel written by Gary Russell and based on the long-running British science fiction television series Doctor Who. It features the Eighth Doctor and Sam and includes brief appearances by the characters of Stacy and Ssard, created by Russell for the Radio Times Doctor Who comic strip.

Gary Russell is a British freelance writer, producer and former child actor. As a writer, he is best known for his work in connection with the television series Doctor Who and its spin-offs in other media. As an actor, he is best known for playing Dick Kirrin in the British 1978 television series The Famous Five.