Recurrence of use is when someone begins using a substance again after having made the decision to stop. The highest risk for recurrence of substance use disorder symptoms occurs during the first 90 days following the initial intervention. The risk for recurrence of symptoms decreases after 90 days. This indicates that individuals attempting to recover from substance use disorder need the most intensive support during this first 3-month period, as individuals are experiencing substantial physiological, psychological, and social changes during this early recovery phase. There is typically a greater sensitivity to stress and lowered sensitivity to reward that makes continued recovery challenging.