Hate and love (including romantic love and abandonment rage) are closely linked in the brain. Both produce energy. If an expected reward appears unattainable, the cortex signals the amygdalae and triggers rage, which may not be directed at the lost reward but at another individual. (Fisher, Helen. Why We Love. p 148-150. NY:Henry Holt and Company, 2004.)
Refer to Emotions and Feelings for additional information.