Relapse refers to the recurrence of symptoms or behaviors related to a particular condition or problem after a period of improvement or remission. In the context of addiction, relapse refers to the return to drug or alcohol use after a period of abstinence. Research on relapse often focuses on identifying risk factors and triggers that increase the likelihood of relapse, as well as developing strategies for preventing and managing relapse. This research can involve studying biological, psychological, and environmental factors that contribute to relapse, as well as developing and testing interventions to help individuals maintain recovery and avoid relapse.