Brexanolone, a neurosteroid antidepressant, vindicates the GABAergic deficit hypothesis of depression and may foster resilience

F1000Res. 2019 May 29;8:F1000 Faculty Rev-751. doi: 10.12688/f1000research.18758.1. eCollection 2019.


The GABAergic deficit hypothesis of depression states that a deficit of GABAergic transmission in defined neural circuits is causal for depression. Conversely, an enhancement of GABA transmission, including that triggered by selective serotonin reuptake inhibitors or ketamine, has antidepressant effects. Brexanolone, an intravenous formulation of the endogenous neurosteroid allopregnanolone, showed clinically significant antidepressant activity in postpartum depression. By allosterically enhancing GABA A receptor function, the antidepressant activity of allopregnanolone is attributed to an increase in GABAergic inhibition. In addition, allopregnanolone may stabilize normal mood by decreasing the activity of stress-responsive dentate granule cells and thereby sustain resilience behavior. Therefore, allopregnanolone may augment and extend its antidepressant activity by fostering resilience. The recent structural resolution of the neurosteroid binding domain of GABA A receptors will expedite the development of more selective ligands as a potential new class of central nervous system drugs.

Keywords: GABA receptor; Major depressive disorder; allopregnanolone; anxiety; neurosteroid; postpartum depression; rapid acting antidepressant.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Antidepressive Agents / therapeutic use*
  • Depression / drug therapy*
  • Depression, Postpartum / drug therapy
  • Drug Combinations
  • Female
  • GABA Modulators / therapeutic use*
  • Humans
  • Neurosteroids / therapeutic use
  • Pregnanolone / therapeutic use*
  • Receptors, GABA-A / drug effects*
  • beta-Cyclodextrins / therapeutic use*


  • Antidepressive Agents
  • Drug Combinations
  • GABA Modulators
  • Neurosteroids
  • Receptors, GABA-A
  • beta-Cyclodextrins
  • brexanolone
  • Pregnanolone