Longitudinal Changes Of Cognitive Function And Regional Brain Structure In Remitted Geriatric Depression.

Objective: Growing evidences suggest that the abnormality of hippocampal volume and function may occur in the process of depression. We aimed to investigate the association between hippocampal volumes changes and neuropsychological performance in two groups.Methods: In this longitudinal study, we calculated the hippocampal volume of 40 remitted geriatric depressed (RGD) patients and 36 healthy participants (control group) at baseline. And after follow up, we conducted the same process in 14 RGD patients and 19 healthy controls. Psychopathology and neuropsychological test was assessed at baseline phase and then after follow-up.Results:Cognitive function1. At baseline, there were no significant differences in age,gender,year of education and MMSE score between RGD and HC group. However, in some specific domain of cognitive function, such as AVLT,SDMT,TMT A&B and DST, RGD group showed significant poorer performance than HC.2. After follow up, compared to HC group, RGD only exhibited decreased score in AVLT and DST. From baseline to follow-up, RGD show declined score in MMSE,AVLT,DST to some degree. the performance of SDMT,TMT-A&B were improved, and the changes in TMT-A&B were significant. No significant changes were found in HC. Gray/white matter volume1. No significant differences in volumes of gray/white matter were found between RGD and HC. After follow-up, the white matter volumes of right precentral gyrus and left fusiform gyrus, and the gray matter volume of left middle temporal gyrus and the gray matter volume of left middle temporal gyrus in RGD were larger than HC.2. From baseline to follow-up, the white matter volume of left middle frontal gyrus and middle temporal gyrus, gray matter volume of right middle occipital gyrus and bilateral lentiform nucleus were increased significant in RGD. No significant changes were found in HC group.3. Correlation analysis suggested that the increased gray matter volume of right middle occipital gyrus was negative related to the decreased score of MMSE. Hippocampal volumeFrom baseline to follow-up, we found significant improvement of performance in Trail Making Test-A (P=0.038) and Test-B (P=0.032), and the right hippocampal volume increased mildly in RDG. Meanwhile, in RGD patients, positive correlations were seen between the changes in right hippocampal volumes and SDMT scores (r=0.675, P=0.008), and changes in left hippocampal volumes and MMSE scores (r=0.743, P=0.002).The integrity of long association fiber tracts1,At baseline, the FA value of left cingulate fasciculus(posterior) in RGD was lower than HC. After follow-up, the FA value of right frontooccipital fasciculus in RGD was lower than HC.2,From baseline to follow-up, the FA value of splenium of corpus callosum was decreased significantly in RGD. In HC group, the FA value of left cingulate fasciculus (middle) exhibited significant reduce.3,Correlation analysis showed that the decreased FA value of splenium of corpus callosum was negatively related to the increase of SDMT score.Conclusions: Our findings suggesting that regional brain structure related cognitive impairment and previously addressed abnormal regional brain structure might represent a state rather than a permanent trait of the depressive disorder. Additionally, our study indicates that effective antidepressants treatment might postpone and even revise the deterioration of abnormality in regional brain structure to some degree.Limitations: The RGD patients recruited in this study had been received various antidepressants treatments during the follow-up period. Moreover, 26 of the 40 patients participated in the initial study were drop-out from the follow-up study due to the recurrent depressive illness, suicide and other reasons.Part 2: Association study between ACE Insertion/Deletion polymorphism and regional brain volume of gray matter,white matter and cognitive function in RGD patientsObjective: The aim of this study was to investigate the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and structural abnormalities in remitted geriatric depression (RGD), and test the relationship of neuropsychological performances and regional white matter volumes.Methods: 31 RGD patients were recruited and neuropsychological tests, magnetic resonance imaging (MRI) and genotype of ACE I/D were examined for each subject. The differences in regional white matter volume were tested between I homozygotes and D-allele carriers (I/D or D/D genotype) by optimized VBM.Results: 1,D-allele carriers exhibited significantly smaller white matter volumes of right superior frontal gyrus (SFG) and right anterior cingulated gyrus (ACG), but had larger volumes of left middle temporal gyrus (MTG) and right middle occipital gyrus (MOG) than I homozygotes (P<0.001). Meanwhile, there was a significant positive correlation between white matter volume enlargement of left MTG and Symbol Digit Modalities Test (SDMT) (r=0.456, P=0.043), and the reduction of right ACG was negatively related to Clock Drawing Test (CDT) performance (r =?0.445, P = 0.050) in D-allele carriers.2,Compared to I homozygotes, D-allele carriers exhibited significantly decreased gray matter volumes of left frontal lobe sub-gyral. In D carriers, there was a negative correlation between the decreased gray matter volumes of left frontal lobe sub-gyral and TMT-B time.Conclusion: The findings suggest that ACE can modulate the pathology of RGD, the left MTG,right ACG and left frontal lobe sub-gyral might be involved in the pathophysiology of cognitive dysfunction in RGD patients.