title: No change in N-acetyl aspartate in first episode of moderate depression after antidepressant treatment: (1)H magnetic spectroscopy study of left amygdala and left dorsolateral prefrontal cortex.
abstract: BACKGROUND
  The role of brain metabolites as biological correlates of the intensity, symptoms, and course of major depression has not been determined. It has also been inconclusive whether the change in brain metabolites, measured with proton magnetic spectroscopy, could be correlated with the treatment outcome.
  
  
  METHODS
  Proton magnetic spectroscopy was performed in 29 participants with a first episode of moderate depression occurring in the left dorsolateral prefrontal cortex and left amygdala at baseline and after 8 weeks of antidepressant treatment with escitalopram. The Montgomery-Asberg Depression Rating Scale, the Hamilton Rating Scale for Depression, and the Beck Depression Inventory were used to assess the intensity of depression at baseline and at the endpoint of the study. At endpoint, the participants were identified as responders (n=17) or nonresponders (n=12) to the antidepressant therapy.
  
  
  RESULTS
  There was no significant change in the N-acetyl aspartate/creatine ratio (NAA/Cr) after treatment with antidepressant medication. The baseline and endpoint NAA/Cr ratios were not significantly different between the responder and nonresponder groups. The correlation between NAA/Cr and changes in the scores of clinical scales were not significant in either group.
  
  
  CONCLUSIONS
  This study could not confirm any significant changes in NAA after antidepressant treatment in the first episode of moderate depression, or in regard to therapy response in the left dorsolateral prefrontal cortex or left amygdala. Further research is necessary to conclude whether NAA alterations in the first episode of depression could possibly be different from chronic or late-onset depression, and whether NAA alterations in stress-induced (reactive) depression are different from endogenous depression. The potential role of NAA as a biomarker of a treatment effect has yet to be established.
authors.affiliation: University Department of Psychiatry, Clinical Hospital Center Zagreb, Zagreb, Croatia ; University North, Varaždin, Croatia.
authors.forename: Maja
authors.initials: M
authors.lastname: Bajs Janović
authors.affiliation: Polyclinic Neuron, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.
authors.forename: Petra
authors.initials: P
authors.lastname: Kalember
authors.affiliation: University Department of Psychiatry, Clinical Hospital Center Zagreb, Zagreb, Croatia ; University North, Varaždin, Croatia.
authors.forename: Spiro
authors.initials: S
authors.lastname: Janović
authors.affiliation: Polyclinic Neuron, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia.
authors.forename: Pero
authors.initials: P
authors.lastname: Hrabač
authors.affiliation: University Department of Psychiatry, Clinical Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Petra
authors.initials: P
authors.lastname: Folnegović Grošić
authors.affiliation: Psychiatric Hospital Sveti Ivan, Zagreb, Croatia.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Grošić
authors.affiliation: University Department of Radiology, Clinical Hospital Center Zagreb, Zagreb, Croatia.
authors.forename: Marko
authors.initials: M
authors.lastname: Radoš
authors.affiliation: Polyclinic Neuron, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia ; Psychiatric Clinic Vrapče, Zagreb, Croatia.
authors.forename: Neven
authors.initials: N
authors.lastname: Henigsberg
keywords: N-acetyl-aspartate; antidepressant; depression; spectroscopy