Abnormal neural activity in the patients with remitted geriatric depression: a resting-state functional magnetic resonance imaging study.

OBJECTIVE: To investigate regional activity abnormalities of first-episode remitted geriatric depression (RGD) using a resting-state functional magnetic resonance imaging (fMRI) in closely matched patients and healthy controls, and to examine the relationship between performances on neuropsychological tests and regional activity abnormalities.

METHOD: A newly reported regional homogeneity approach was used to analyze blood oxygen level-dependent fMRI data on resting state in 18 patients with remitted geriatric depression and 14 well-matched healthy controls. All subjects were measured by neuropsychological tests.

RESULTS: Decreased regional homogeneity (ReHo) in remitted geriatric depression distributed over the frontal, temporal and parietal lobes. In addition, increased ReHo were found mainly in the putamen, frontal and parietal lobes. The RGD patients performed significantly worse in the delayed recall of Rey Auditory Verbal Learning Test (RAVLT) and Trail Making Test A and B (seconds) when compared with the control group. And there are significant negative correlations between ReHo values of right putamen, left superior frontal gyrus and Trail Making Test A (seconds) (r=-0.583, P=0.023; r=-0.598, P=0.018, respectively), Trail Making Test B (seconds) (r=-0.587, P=0.021; r=-0.545, P=0.036, respectively) in the patients with RGD.

LIMITATIONS: This study is cross-sectional, therefore it cannot determine whether abnormal brain activation is a state marker or trait marker of RGD in resting-state fMRI.

CONCLUSION: Our study reveals that RGD is associated with abnormal activity of certain brain regions, which are believed to be involved in the psychopathology and pathophysiology of executive function in remitted geriatric depression.