Regional Cortical Thickness and Subcortical Volume Changes Are Associated with Cognitive Impairments in the Drug-Naive Patients with Late-Onset Depression

Abstract

Previous studies have shown an association between late-onset depression (LOD) and cognitive impairment in older adults. However, the neural correlates of this relationship are not yet clear. The aim of this study was to investigate the differences in both cortical thickness and subcortical volumes between drug-naive LOD patients and healthy controls and explore the relationship between LOD and cognitive impairments. A total of 48 elderly, drug-naive patients with LOD and 47 group-matched healthy control subjects underwent 3T MRI scanning, and the cortical thickness was compared between the groups in multiple locations, across the continuous cortical surface. The subcortical volumes were also compared on a structure-by-structure basis. Subjects with LOD exhibited significantly decreased cortical thickness in the rostral anterior cingulate cortex, the medial orbitofrontal cortex, dorsolateral prefrontal cortex, the superior and middle temporal cortex, and the posterior cingulate cortex when compared with healthy subjects (all p<0.05, false discovery rate corrected). Reduced volumes of the right hippocampus was also observed in LOD patients when compared with healthy controls (p<0.001). There were significant correlations between memory functions and cortical thickness of medial temporal, isthmus cingulate, and precuneus (p<0.001). This study was the first study to explore the relationships between the cortical thickness/subcortical volumes and cognitive impairments of drug-naive patients with LOD. These structural changes might explain the neurobiological mechanism of LOD as a risk factor of dementia.

Structural brain changes associated with depressive symptoms in the elderly with Alzheimer's disease

“…Thinning in the superior temporal cortex has been described for patients with major depressive disorder 35. A similar pattern of cortical atrophy including temporal and parietal regions was observed in non-demented subjects with late-life depression (LLD) 36 37. It has also been shown that psychotherapy-resistant patients with LLD compared with responders have thinner cortex in several regions, including paracentral, precuneus and posterior cingulate cortex 38.…”

Neuroanatomical correlates of late-life depression and associated cognitive changes

“…However, we had only N ¼ 13 men in the cohort so the absence of cortical thinning in men may represent a type 2 error. Volumetric reduction in the frontal, temporal, and parietal regions in LOD compared with the EOD has been reported (Almeida et al, 2003;Truong et al, 2013) as well as prefrontal thinning in LOD compared with healthy (Almeida et al, 2003;Lim et al, 2012) in samples based on both genders. Because depression is more common and severe in women with higher recurrence rates and poorer response to selective serotonin reuptake inhibitors (Kendler and Gardner, 2014;Press, 2014;Szadoczky and Rihmer, 2002), gender differences in the pathophysiology of depression seems likely.…”

Blockade of Astrocytic Glutamate Uptake in the Prefrontal Cortex Induces Anhedonia

“…MDD is associated with regional volumetric changes throughout a variety of limbic regions; however, all areas of the PFC consistently display volumetric reductions in imaging studies (Bremner et al, 2002;Drevets, 2000;Drevets et al, 1997;Lim et al, 2012;Malykhin et al, 2011;Salvadore et al, 2011). Decreases in PFC volume have been attributed to reductions in glial cells (Cotter et al, 2002;Hercher et al, 2009;Ongur et al, 1998;Rajkowska, 2000;Rajkowska et al, 1999) and to a lesser extent, neuronal atrophy (Cotter et al, 2002;Law and Harrison, 2003;Rajkowska, 2000;Rajkowska et al, 1999).…”