title: Hippocampal glutamate is increased and associated with risky drinking in young adults with major depression.
abstract: BACKGROUND
  Risky drinking in young people is harmful, highly prevalent and often complicated by comorbid mental health problems that compound alcohol-induced impairment. The hippocampus and the glutamate system have been implicated in the pathophysiology of alcoholism and depression. This study aimed to determine whether risky drinking is associated with glutamate levels recorded within the hippocampus of young adults with major depression.
  
  
  METHODS
  Sixty-three young persons with major depression (22.1±3.1 years; 65% female) and 38 healthy controls were recruited. Participants completed the alcohol use disorder identification test and underwent proton magnetic resonance spectroscopy to measure in vivo glutamate levels within the hippocampus following a period of at least 48h of abstinence.
  
  
  RESULTS
  Young adults with depression had significantly increased hippocampal glutamate levels and a positive association between the level of alcohol use and glutamate. Regression analysis revealed that higher levels of hippocampal glutamate were predicted by having increased levels of risky drinking and depression.
  
  
  CONCLUSIONS
  Small sample sizes for testing diagnosis by risky drinking interaction and use of creatine ratios rather than the absolute concentrations of glutamate.
  
  
  CONCLUSIONS
  The hippocampus is a critical region; given its role in learning and memory as well as mood regulation, and the neurochemical changes observed in this study may precede structural changes, which are commonly observed in both depression and alcohol misuse. These findings suggest that young adults with major depression who engage in risky drinking may be at increased risk of glutamate excitotoxicity.
authors.affiliation: Clinical Research Unit, Brain and Mind Research Institute, University of Sydney, Camperdown, Australia. Electronic address: daniel.hermens@sydney.edu.au.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Hermens
authors.affiliation: Clinical Research Unit, Brain and Mind Research Institute, University of Sydney, Camperdown, Australia.
authors.forename: Kate M
authors.initials: KM
authors.lastname: Chitty
authors.affiliation: Clinical Research Unit, Brain and Mind Research Institute, University of Sydney, Camperdown, Australia.
authors.forename: Rico Sc
authors.initials: RS
authors.lastname: Lee
authors.affiliation: Clinical Research Unit, Brain and Mind Research Institute, University of Sydney, Camperdown, Australia.
authors.forename: Ashleigh
authors.initials: A
authors.lastname: Tickell
authors.affiliation: Drug Health Services, Royal Prince Alfred Hospital, Camperdown, Australia; Sydney Medical School, University of Sydney, Camperdown, Australia.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Haber
authors.affiliation: Clinical Research Unit, Brain and Mind Research Institute, University of Sydney, Camperdown, Australia.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Naismith
authors.affiliation: Clinical Research Unit, Brain and Mind Research Institute, University of Sydney, Camperdown, Australia.
authors.forename: Ian B
authors.initials: IB
authors.lastname: Hickie
authors.affiliation: Clinical Research Unit, Brain and Mind Research Institute, University of Sydney, Camperdown, Australia.
authors.forename: Jim
authors.initials: J
authors.lastname: Lagopoulos
mesh_terms: D000428:Alcohol Drinking / Q000378:metabolism*; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000378:metabolism*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D008297:Male; D066244:Proton Magnetic Resonance Spectroscopy; D012309:Risk-Taking; D055815:Young Adult
chemical_list: D018698:Glutamic Acid
keywords: Alcohol; Depression; Glutamate; Hippocampus; Magnetic resonance spectroscopy