Blood glutamate levels in major depression with antidepressants and benzodiazepines: A 6-month prospective cohort study.

AIM OF THE STUDY: Our study aims at analyzing blood glutamate levels at three time points in patients on antidepressants and benzodiazepines across different subgroups.

METHODS

In the 6-month METADAP cohort study, blood glutamate levels were measured in 60 patients with major depression at baseline, 3 months (M3), and 6 months (M6) after starting antidepressant treatment. All patients received a co-prescription with benzodiazepines. Mixed-effect linear regression models were used to analyze the correlation of glutamate levels over time among responders, non-responders, remitters, and non-remitters, adjusting for multiple confounders.

RESULTS

Glutamate blood levels showed a significant decrease. Glutamate levels decreased from M0 to M3 across all subgroups. Responders and remitters showed a further decline from M3 to M6 while they increased non-significantly from M3 to M6 among non-responders and non-remitters. Responders showed a decrease of 3.38μmol/L [95% CI (-4.94; -1.82), P<0.001], while remitters showed a decrease of 1.34μmol/L [95% CI (-2.41; -0.27), P=0.014].

CONCLUSION

Glutamate blood levels decreased from M0 to M3 across all groups but varied from M3 to M6: responders and remitters continued to decline, while non-responders and non-remitters showed a non-significant increase. These results should be replicated and further explained.