Fat is Good for Depression?

Two days ago British advocacy groups released reports that poor modern diets were at the root of increased rates of mental illness. In particular, they linked obesity and mental illness. Now comes news from a study claiming that leptin--a fat producing protein--helps alleviate depression. The study was done in rats and uses stress as a proxy for depression, so it doesn't necessarily correlate with what might be expected in humans. Still, it is interesting. And proof, once again, what a topsy-turvy world is mental health research.