STRUCTURAL BRAIN CHANGES IN LATE ONSET DEPRESSION

Abstract

AbstractBackgroundStructural brain changes in grey matter in late‐life depression (LLD) remains an intriguing area of research. Furthermore, late‐onset depression (LOD) has been frequently associated with general medical comorbidities, cognitive deficits and structural abnormalities of the brain. This magnetic resonance imaging (MRI) study compares the grey matter volume of elderly people with and without major depression (DSM‐IV‐TR criteria), as well LOD, early onset depression (EOD) and controls.MethodThe sample consisted of elders with and without depression from community. Brain MRI scans were processed using statistical parametric mapping and voxel‐based morphometry.ResultSixty three elders with depression and 24 controls were enrolled. Demographic characteristics were analyzed and sex showed a statistically significant difference (p = 0.001) between the groups, with males representing 17.5% of the patient sample and 54.2% of the control sample. Furthermore, MMSE and CAMCOG showed a statistically significant difference between groups (p<0.0001 for both tests), with the control group performing better. Although we excluded cases of patients with below‐expected performance according to the neuropsychological assessment, it is likely that this cognitive impairment presented by the patient group is secondary to major depressive disorder. We did not find a significant volumetric difference between depressed and control group (CG). We used the age of onset of depression as another way of classifying the patient sample and compared it with the control group regarding key demographic and clinical characteristics. Gender was statistically significant different between groups, however there were only 2 male subjects in the EOD group, making it not possible to control the analysis by gender. Compared to the CG (n = 24), the LOD group (n = 32) showed a statistically significant volumetric reduction with correction for multiple comparisons in the right thalamus (464 voxels; peak xyz coordinates = 14 ‐10 16; Z = 4, 62; p‐FWEcorr = 0.052) when using the whole brain for multiple comparisons.ConclusionOur findings support the use of regional brain atrophy as a tool to better understand LOD.