Ms. X had taken varenicline only sporadically until late 2008, when she began taking 1 mg twice daily for 2 months. She discontinued the medication abruptly, secondary to ongoing insomnia that impaired her work function. During the following few days, she began to feel "strange," describing confusion, disorientation, and perceptual changes. While listening to music, she heard a "sinister, evil voice." She saw "movements in everything," including fractal patterns on the leaves of trees, and an uncomfortable intensity of color and contrast. She had tactile sensitivity to the point where to touch an object "made it feel like [her] skin and muscles were being ripped apart." Over the week, the sensory misperceptions improved, but her thoughts "felt too big," with associated depersonalization. Over the month, she received relief from benzodiazepines but had "irrational" fears, insomnia, and visual distortions, including objects looking "shiny," the ground appearing to move, or lights appearing "strobe-like." She continued to experience visual changes and memory deficits. Her complete blood count, electrolytes, liver function tests, ceruloplasmin levels, thyroid-stimulating hormone test, and ophthalmic consultation were all normal.