Answer: Unfortunately social stress can last for a long while, depending on the individual who has experienced the painful situation. This seems to be particularly true for stressful social situations that cause strong effects, like ostracism, bullying and other forms of relational aggression.
Social stress can last for years because even a one-time incident can be relived just by thinking about it. Researchers find that mental reliving can feel just as painful as the initial event. They note that this may make social stressors more damaging than physical aggression since physical pain fades as injuries heal while psychological pain can continue indefinitely. Notably, though, there do seem to be gender differences in which type of aggression feels more harmful.
Not all tweens who experience a social stressor will experience long-term pain, however. In the case of social exclusion, all kids will initially feel pain, but most will mentally cope and not move onto deeper, longer-lasting stages of feeling hurt. Kids who ruminate on the situation, however, may get so overwhelmed that their mental resources are exhausted. This lays the groundwork for the most damaging effects, such as suicidal thoughts.
Williams, Kipling D., and Nida, Steve A. Ostracism: Consequences and Coping. Current Directions in Psychological Science. 2011. 20(2): 71-75.