Three alternative views regarding how Major Depressive Disorder (MDD) alters emotional reactivity have been featured in the literature: positive attenuation (reduced positive reactivity), negative potentiation (increased negative reactivity), and emotion context insensitivity (ECI; reduced positive and negative reactivity). Although empirical studies have accumulated on emotional reactivity in MDD, this report is to our knowledge the first systematic quantitative review of this topic area. In omnibus analyses of 19 laboratory studies comparing the emotional reactivity of healthy individuals to that of individuals with MDD, MDD was characterized by reduced emotional reactivity to both positively and negatively valenced stimuli, with the reduction larger for positive stimuli (d=-.53) than for negative stimuli (d=-.25). Results were similar when 3 major emotion response systems (self-reported experience, expressive behavior, and peripheral physiology) were analyzed individually. The ECI view of emotional reactivity in MDD is well supported by laboratory data. Implications for the understanding of emotions in MDD are discussed.