The broad diagnostic category of DSM Major Depressive Disorder (MDD) is heterogeneous, and we suggest that it can be subdivided into at least three groups: those with Negative-emotionality who experience strong negative emotionality such as misery, anxiety, guilt, fatigue etc; Hyper-emotionality who experience strong emotions in both negative and positive directions; and Hypo-emotionality who experience weak or blunted emotions. This model was tested using an internet survey of 251 subjects that measured strength of depressive symptoms; and strength and directionality of emotions. All three emotionality groups were significantly more depressed than controls. This indicates that depressive symptoms may be a consequence of at least three different emotional patterns. One implication may be that different emotionality sub-types could benefit from different treatments.