In 1971, Dick's marriage to Nancy Hackett broke down, and she moved out of their house in Santa Venetia, California. Having abused amphetamine for much of the past decade (stemming in part from his need to maintain a prolific writing regimen due to the financial exigencies of the science fiction field), he allowed other drug users to move into the house. Following the release of 21 novels between 1960 and 1970, these developments were exacerbated by unprecedented periods of writer's block, with Dick ultimately failing to publish new fiction until 1974.