This chapter discusses in detail the efficacy of four commonly studied emotion regulation strategies: cognitive reappraisal, expressive suppression, emotional thought suppression, and emotional disclosure. It discusses whether each strategy works to modify one or all aspects of emotion and also whether each strategy has any hidden costs to the individual, including to their interpersonal relationships and to their health. Emotion regulation strategies thus differ in their cognitive consequences. Cognitive reappraisal seems to be an emotion regulation strategy that alters many components of emotion. Suppression impairs the recall of details of an emotional event, whereas reappraisal does not. Suppression may impair the suppressor's responsiveness in a social encounter—that is, it may impair appropriate contingent responses and impede the coordination with the interaction partner. D. M. Wegner's model of mental control proposes different explanations for the rebound of suppressed thoughts. The absence of an emotional rebound may be due to people's prior experience with controlling intrusive emotional thoughts.