I absolutely believe that sugar and other foods that aren't necessarily good for us have a tremendous impact on hormones. Since depression tends to be a severe hormonal imbalance, you can see how sugar consumption and manic rages go hand in hand. I had this happen to me over the summer after a really bad binge. Hubby got home just in time to stop me from shaving my head and mutilating myself. It wasn't pretty.
If you experience depression symptoms, try to avoid processed sugars as much as possible.