Plasma gamma-aminobutyric acid (GABA) levels and posttraumatic stress disorder symptoms in trauma-exposed women: a preliminary report

Psychopharmacology (Berl). 2021 Jun;238(6):1541-1552. doi: 10.1007/s00213-021-05785-z. Epub 2021 Feb 23.

Abstract

Rationale: Aberrations in the stress response are associated with posttraumatic stress disorder (PTSD) symptom development, maintenance, and severity. Gamma-aminobutyric acid (GABA), the brain's primary inhibitory neurotransmitter, may play a key role in stress recovery.

Objectives: In this preliminary study, we examined whether plasma GABA levels differed between women with PTSD and trauma-exposed healthy controls.

Methods: Thirty participants provided plasma samples during two phases of the menstrual cycle: the early follicular phase and the mid-luteal phase. During each phase, blood was drawn after 45 min of rest, and after mild and moderately stressful psychophysiological tasks. Plasma GABA levels were measured using HPLC-mass spectrometry (LC-MS/MS).

Results: In analyses using PTSD diagnosis as a categorical group variable, women with and without a diagnosis of PTSD did not differ in plasma GABA levels (ps > .18). However, in analyses examining PTSD symptom severity as a continuous variable, there was a trend-level positive association between more severe PTSD symptoms and higher plasma GABA levels across the four blood draws (p = .06). In analyses examining DSM-IV PTSD symptom clusters separately, dysphoria symptoms were positively and significantly associated with plasma GABA levels (p = .03). Similarly, there was a trend-level positive association between avoidance cluster symptoms and plasma GABA levels (p = .06). Plasma GABA levels were not modulated by experimentally induced stress or menstrual cycle phase.

Conclusions: Dysregulation in GABA may be a neurobiological marker and/or potential treatment target for women with PTSD symptom profiles characterized by prominent dysphoria and avoidance cluster symptoms.

Keywords: Avoidance; Dysphoria; Fear conditioning; Female; Loud tones; Menstrual cycle; Neurotransmitter; Prepulse inhibition task; Psychophysiology; Traumatic stress.

MeSH terms

  • Adult
  • Chromatography, Liquid
  • Female
  • Follicular Phase / physiology
  • Humans
  • Luteal Phase / physiology
  • Menstrual Cycle / physiology*
  • Middle Aged
  • Stress Disorders, Post-Traumatic / blood*
  • Stress Disorders, Post-Traumatic / physiopathology
  • Tandem Mass Spectrometry
  • Young Adult
  • gamma-Aminobutyric Acid / blood*
  • gamma-Aminobutyric Acid / physiology

Substances

  • gamma-Aminobutyric Acid