<qa>  What is the effect of diabetes alone?Hypothesis: Levels of glutamate and aspartate creatine ratios will be lower in patients with combined Type 2 Diabetes and MDD when compared with non-depressed diabetic patients and healthy controls. Our pilot data provide little basis to expect a simple effect of diabetes alone but do not rule out an interaction such that effects are only seen, or are worsened, by the combination of diabetes and depression. The inclusion of a depressed non-diabetic group in the current design will make it possible to evaluate whether the observed effect in the doubly-diagnosed group is best viewed as an effect of depression alone or as an interaction in which diabetes plays a role. 