title: Oxidative stress and depressive symptoms in older adults: A magnetic resonance spectroscopy study.
abstract: Major depression is common in older adults and associated with greater health care utilisation and increased risk of poor health outcomes. Oxidative stress may be implicated in the pathophysiology of depression and can be measured via the neurometabolite glutathione using proton magnetic resonance spectroscopy ((1)H-MRS). This study aimed to examine the relationship between glutathione concentration and depressive symptom severity in older adults 'at-risk' of depression. In total, fifty-eight older adults considered 'at-risk' of depression (DEP) and 12 controls underwent (1)H-MRS, medical and neuropsychological assessments. Glutathione was measured in the anterior cingulate cortex (ACC), and calculated as a ratio to creatine. Depressive and anxiety symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS). Compared to controls, DEP patients had increased glutathione/creatine ratios in the ACC (t=2.7, p=0.012). In turn, these increased ratios were associated with greater depressive symptoms (r=0.28, p=0.038), and poorer performance on a verbal learning task (r=-0.28, p=0.040). In conclusion, depressive symptoms in older people are associated with increased glutathione in the ACC. Oxidative stress may be pathophysiologically linked to illness development and may represent an early compensatory response. Further research examining the utility of glutathione as a marker for depressive symptoms and cognitive decline is now required.
authors.affiliation: Healthy Brain Ageing Program; Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia; Clinical Research Unit, Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia. Electronic address: shantel.duffy@sydney.edu.au.
authors.forename: Shantel L
authors.initials: SL
authors.lastname: Duffy
authors.affiliation: Clinical Research Unit, Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
authors.forename: Jim
authors.initials: J
authors.lastname: Lagopoulos
authors.affiliation: Healthy Brain Ageing Program; Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia; Clinical Research Unit, Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
authors.forename: Nicole
authors.initials: N
authors.lastname: Cockayne
authors.affiliation: Healthy Brain Ageing Program; Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia; Clinical Research Unit, Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Hermens
authors.affiliation: Healthy Brain Ageing Program; Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia; Clinical Research Unit, Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
authors.forename: Ian B
authors.initials: IB
authors.lastname: Hickie
authors.affiliation: Healthy Brain Ageing Program; Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia; Clinical Research Unit, Brain & Mind Research Institute, The University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Naismith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism; D003863:Depression / Q000378:metabolism* / Q000523:psychology*; D003865:Major Depressive Disorder / Q000378:metabolism* / Q000523:psychology*; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D006179:Gyrus Cinguli / Q000378:metabolism; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D018384:Oxidative Stress; D066244:Proton Magnetic Resonance Spectroscopy; D012720:Severity of Illness Index; D014706:Verbal Learning
chemical_list: D005978:Glutathione; D003401:Creatine
keywords: Anterior cingulate cortex; Depression; Glutathione; Oxidative stress; Proton magnetic resonance spectroscopy