A magnetic resonance imaging study of the entorhinal cortex in treatment-resistant depression

• Published in: Psychiatry research. Neuroimaging Vol. 163; no. 2; pp. 133 - 142
• Main Authors: Furtado, Christina P, Maller, Jerome J, Fitzgerald, Paul B
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 15.07.2008; Elsevier
• Subjects: Adult; Adult and adolescent clinical studies; Antidepressive Agents - therapeutic use; Atrophy; Biological and medical sciences; Brain - pathology; Depression; Depressive Disorder, Major - diagnosis; Depressive Disorder, Major - drug therapy; Depressive Disorder, Major - physiopathology; Depressive Disorder, Major - psychology; Dominance, Cerebral - physiology; Drug Resistance; Entorhinal Cortex - pathology; Female; Humans; Image Processing, Computer-Assisted; Imaging; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Mood disorders; Psychiatric illness; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Radiology; Reference Values; Sex Factors; Volumetric analysis; Psychiatric illness; Volumetric analysis; Imaging; Mood disorder; Human; Treatment resistance; Central nervous system; Depression; Nuclear magnetic resonance imaging; Encephalon; Entorhinal cortex; Mental disorder; Medical imagery
• ISSN: 0925-4927; 1872-7506
• DOI: 10.1016/j.pscychresns.2007.11.005

Abstract Despite a growing interest in this area, we continue to lack an understanding of the pathophysiology of depression and of treatment-resistant depression (TRD) in particular. The role of the medial temporal lobe, particularly the hippocampus, has been widely implicated in the aetiology of depression. However, related structures such as the entorhinal cortex have not been systematically examined. This research study aimed to examine possible abnormalities in the volume of the entorhinal cortex (ERC) in TRD patients. A group of 45 TRD patients and 30 healthy age- and sex-matched controls underwent magnetic resonance imaging (MRI). ERC volumes were manually traced from MRI data using ANALYZE software. An analysis of variance was conducted between subject groups and in the sexes separately while controlling for the effects of brain size via intracranial volume (ICV). Results revealed significant reductions in the volume of the left ERC of female patients. Although preliminary, our findings suggest that anatomical abnormalities in the ERC may confer vulnerability to treatment resistance. Confirmatory longitudinal studies are required to determine whether these abnormalities predate the onset of depression or are the result of a more chronic, treatment-resistant course of illness.