Transcranial direct current stimulation may modulate extinction memory in posttraumatic stress disorder.

Area of Science:

• Neuroscience
• Psychiatry
• Clinical Psychology

Background:

• Posttraumatic stress disorder (PTSD) is characterized by impaired fear extinction and recall.
• The ventromedial prefrontal cortex (vmPFC) plays a crucial role in fear extinction learning and memory retention.
• Noninvasive brain stimulation techniques are being explored for treating psychopathology.

Purpose of the Study:

• To investigate if transcranial direct current stimulation (tDCS) applied during extinction learning or consolidation can improve fear extinction recall in veterans with PTSD.
• To pilot the efficacy of tDCS targeting the vmPFC for enhancing fear memory extinction.

Main Methods:

• Twenty-eight veterans with PTSD underwent a 2-day fear conditioning, extinction, and recall paradigm.
• Participants received 2 mA anodal tDCS over AF3 (targeting vmPFC) for 10 minutes.
• tDCS was administered either during extinction learning (n=14) or during extinction consolidation (n=14).
• Skin conductance reactivity (SCR) was measured as the primary outcome, analyzed using linear mixed effects models.

Main Results:

• Veterans receiving tDCS during extinction consolidation exhibited reduced SCR during early recall compared to those receiving tDCS during extinction learning (p=.08, Cohen's d=.38).
• No significant effect of tDCS was observed on SCR during late extinction.
• Preliminary results indicate a potential benefit of tDCS during the consolidation phase.

Conclusions:

• Applying tDCS during the consolidation of fear extinction shows promise for improving extinction recall in veterans with PTSD.
• These findings support further research into tDCS as an adjunctive therapy for enhancing fear memory extinction in PTSD.