[Correlation of neurochemical metabolism with memory function in young adult patients with first-episode depression studied with proton magnetic resonance spectroscopy].

Objective: To investigate the correlation of neurochemical metabolism in hippocampus with memory function in young adult patients with first-episode depression.
Methods: Twenty patients with first-episode depression (patient group) and fifteen health subjects (control group) were enrolled in the study. The neurochemical metabolism, including the levels of N-acetylaspartate (NAA), Choline (Cho), Creatine (Cr), Myoinositol (mI) were measured by proton magnetic resonance spectroscope (1H-MRS) in bilateral hippocampus. Wechsler Memory Scale (WMS) were used to examine the memory function in both groups.
Results: The memory quotient (89.15 ±6.62) of patient group was significantly lower than that of controls (P <0.01),the scores of long-term memory,short-term memory and immediate memory in patients were also lower than those of controls (P<0.05 or 0.01). In patient group, the ratio of NAA/Cr (1.34 ±0.08) in the left hippocampus was significantly lower than that of control group (P<0.01); and the ratio of mI/Cr in the bilateral hippocampus [(0.63 ±0.13) in left and (0.6 ±0.1) in right] was significantly higher than those in control group (P<0.05). In patient group,the ratio of NAA/Cr in the left hippocampus was positively correlated with WMS scores (P<0.01), and the ratio of mI/Cr in the left hippocampus was negatively correlated with WMS scores (P<0.05).
Conclusion: The memory deficit and abnormal metabolism function of neuron cell in hippocampus coexist in young adult patients with first-episode depression, and the lower NAA/Cr and higher mI/Cr ratio in the left hippocampus may result in the memory deficit.