Escapism was the concept of choosing a diversion based on its ability to enable one to "escape" one's ordinary life.
After describing his desire for an escape from the pressures of being a starship captain to Doctor Phil Boyce only a day previous, Christopher Pike found himself inhabiting a world much like the one he'd detailed, with Vina. He remarked that he now understood Boyce's concerns about his withdrawing from reality. (TOS: "The Cage")
Some people on Turkana IV used drugs as an escape from the poverty and violence that plagued their planet. When Natasha Yar explained this to Wesley Crusher in 2364, he asked how drugs provided an escape, to which she responded that they didn't, but made you belive they did. (TNG: "Symbiosis")