A pilot study of hippocampal volume and N-acetylaspartate (NAA) as response biomarkers in riluzole-treated patients with GAD
European Neuropsychopharmacology, 07/17/2012
Abdallah CG et al. – The preliminary findings support hippocampal NAA and volume as neural biomarkers substantially associated with therapeutic response to a glutamatergic drug.Methods
- Eighteen medication-free adult patients with GAD received 8-week of open-label riluzole.
- Ten healthy subjects served as a comparison group.
- Participants underwent magnetic resonance imaging and spectroscopy at baseline and at the end of Week 8.
- GAD patients who completed all interventions were classified as remitters (n=7) or non-remitters (n=6), based on final Hamilton Anxiety Rating Scale (HAM-A) scores ≤7.
- At baseline, GAD patients had a significant reduction in total hippocampal volume compared to healthy subjects (F(1,21)=6.55, p=0.02).
- This reduction was most pronounced in the remitters, compared to non-remitters and healthy subjects.
- Delta (final-baseline) hippocampal volume was positively correlated with delta NAA in GAD.
- This positive association was highly significant in the right hippocampus in GAD [r=0.81, p=0.002], with no significant association in healthy subjects [Fisher r-to-z p=0.017].
- Across all GAD patients, delta hippocampal volume was positively associated with improvement in HAM-A (rspearman=0.62, p=0.03).