Occasional relapses and minor remissions may appear. The pattern of relapses and remissions varies greatly with each patient. Treatment with tafenoquine prevents relapses after confirmed "P. vivax" malaria. In the season finale, Gary relapses into alcoholism, endangering his marriage. Meanwhile, spurred by the collapse of his romance with Diane, Sam relapses into alcoholism. Unwanted side effects cause people to stop treatment, resulting in relapses. Regimens are available that treat relapses, and new approaches are under test. Nez has struggled with addiction before and during the series she relapses. Meanwhile, Jane relapses into drug addiction and introduces Jesse to heroin. They quickly become a couple, and she relapses into drug addiction, introducing Jesse to heroin. Billy later relapses in his gambling addiction, and the couple briefly separate. David relapses and is readmitted to a mental institution as a young man. A minority have a series of periodic relapses related to the menstrual cycle . After his brother relapses and begins recovering, he returns home with Cam and Booth. In her restlessness, Callie secretly relapses into drug use.