The recency ratio is associated with reduced CSF glutamate in late-life depression.
Glutamate is the principal excitatory neurotransmitter in the central nervous system, and is thought to be involved in the process of memory encoding and storage. Glutamate disturbances have also been reported in psychiatric disorders, such as schizophrenia and major depressive disorder (MDD), and in Alzheimer's disease. In this paper, we set out to study the relationship between cerebrospinal fluid (CSF) glutamate levels and memory performance, which we believe has not been reported previously. In particular, we focused on recall performance broken down by serial position. Our prediction was that the recency ratio (Rr), a novel cognitive marker of intellectual impairment, would be linked with CSF glutamate levels. We studied data from a group of cognitively intact elderly individuals, 28 of whom had MDD, while 19 were controls. Study results indicated that Rr levels, but no other memory score, were inversely correlated with CSF glutamate levels, although this was found only in individuals with late-life MDD. For comparison, glutamine or GABA were not correlated with any memory performance measure.
School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK. Electronic address: d.bruno@ljmu.ac.uk.
Davide
D
Bruno
Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, School of Medicine, New York University, New York City, NY, USA.
Jay
J
Nierenberg
Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, Medical Center, Columbia University, New York City, NY, USA.
Thomas B
TB
Cooper
Department of Psychiatry, School of Medicine, New York University, New York City, NY, USA.
Charles R
CR
Marmar
Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden; UCL Institute of Neurology, London, UK.
Henrik
H
Zetterberg
Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden.
Kaj
K
Blennow
Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba, Japan.
Kenji
K
Hashimoto
Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Department of Psychiatry, School of Medicine, New York University, New York City, NY, USA.
Nunzio
N
Pomara
D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000134:cerebrospinal fluid* / Q000000981:diagnostic imaging / Q000523:psychology; D005260:Female; D018698:Glutamic Acid / Q000134:cerebrospinal fluid*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests
D018698:Glutamic Acid
Glutamate; Major depressive disorder; Memory; Serial position