Clinical Application Of Magnetic Resonance Spectroscopy And Diffusion Tensor Imaging In Adolescent Depression

Objective To expore the correlation of brain biochemical changes of adolescent depression in the frontal white matter and gray matter with memory function by using proton magnetic resonance spectroscopy(1H MRS).Methods Twenty-four first-episode, adolescent depressed patients and twenty-three healthy controls were enrolled in this study. Subjects underwent multivoxel 1H MRS to obtain bilateral metabolite levels from the dorsolateral prefrontal white matter and anterior cingulate gray matter, including N-acetylaspartate(NAA), choline(Cho), creatine(Cr), memory function were measured by Wechsler Memory Scae(WMS).Results The NAA/Cr and Cho/Cr ratios were significantly lower in the left dorsolateral prefrontal white matter of the depressed patients than in that of the controls (p< 0.05). By contrast, the NAA/Cr ratio was significantly lower in the right dorsolateral prefrontal white matter of the depressed patients than in that of the controls (p<0.05). Meanwhile, no significant difference in the Cho/Cr ratio was identified between the two groups (p> 0.05). The NAA/Cr and Cho/Cr ratios in the bilateral anterior cingulate gray matter were also not significantly different between the two groups (p> 0.05). Moreover, no correlation between the metabolite ratios and HDRS scores was observed in both groups (p> 0.05).Statistically significant correlations were determined between the MQ and NAA/Cr values in the left and right dorsolateral prefrontal white matters (left:r=0.593, p< 0.01; right:r= 0.553, p< 0.05) of the patients. Meanwhile, no correlation between the Cho/Cr and MQ values in the left and right dorsolateral prefrontal white matter was observed. No significant correlations were identified between the MQ value and any measured metabolite levels (NAA/Cr, Cho/Cr) in the bilateral anterior cingulate gray matter of the patients. Statistically significant negative correlation were determined between the cognitive impairment and NAA/Cr values in the left dorsolateral prefrontal white matters (r=-0.38, p< 0.01) of the patients. No correlation between the metabolite levels (NAA/Cr, Cho/Cr) and other factors of HAMD in the right dorsolateral prefrontal white matter and the bilateral anterior cingulate gray mattewas observed(p> 0.05). Statistically significant correlations were determined between the visual reproduction (r=0.74,p<0.01), associative learning (r=0.57,p<0.05) and NAA/Cr values in the left dorsolateral prefrontal white matters of the patients. Statistically correlations were determined between the Personal experience (r=0.59,p<0.05), Visual recognition (r=0.47,p<0.05), associative learning (r=0.45,p<0.05) and NAA/Cr values in the right dorsolateral prefrontal white matters of the patients. Statistically negative correlations were determined between the visual reproduction (r=-0.48,p<0.05), along the back and recite (r=-0.57,p<0.05), associative learning (r=0.45,p<0.05) and Cho/Cr values in the left dorsolateral prefrontal white matters of the patients. No correlation between the metabolite levels (NAA/Cr, Cho/Cr) and the factors of WMS in the bilateral anterior cingulate gray mattewas observed(p> 0.05).Conclusion Biochemical abnormalities in prefrontal white matter may occur in the course of adolescent depression. Bilateral anterior frontal white matter NAA/Cr may be associated with memory impairment and related neuropathology.ObjectiveTo expore the changes of the white matter in adolescent depression by using method of Tract-Based Spatial Statistcs (TBSS).MethodsWe employed TBSS to examine WM microstructure in 35 treatment-naive adolescents with clinical depression relative to 40 matched controls. Using TBSS, we examined the difference of fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD) between adolescent patients with depression and controls.ResultsOur analysis revealed abnormal WM microstructure in clinically depressed adolescents. Whole-brain analysis revealed that patients had lower FA values in the body of the corpus callosum (CC) (P<0.01), coupled with elevated RD and MD(P<0.01), and preserved AD(P>0.05). The FA values in the body of the corpus callosum was negatively correlated with Severity of depression (P<0.01).ConclusionOur findings suggest that WM abnormalities are involved in the patho-physiology of depression. Importantly, our findings show that these WM abnormalities are already present early in the course of the disorder.