I have experienced the same cycle of weight gain and depression. Both also run in my family. When events happened in my that were tragic or extremely stressful I ate to medicate myself. It was the way I got up each morning to go on for another day. I had to -I had responsibilities that had to be taken care of
I was on anti-depressents for 10 years--did nothing but gain weight. Was eating a high carb low fat diet. Got off the medication last June. 6 months of depression later went on Atkins. I am feeling better.