Trial results for a study investigating the effect of tDCS timing on safety memory in Posttraumatic Stress Disorder (PTSD) were posted on ClinicalTrials.gov on 2025-10-21, with 62 participants enrolled.
Background
Posttraumatic Stress Disorder (PTSD) is a mental health condition triggered by experiencing or witnessing a terrifying event. It is characterized by symptoms such as intrusive thoughts, avoidance, negative changes in thinking and mood, and changes in arousal and reactivity. Current treatments often involve psychotherapy and medication, but research continues into novel approaches. Understanding how non-invasive brain stimulation, like transcranial direct current stimulation (tDCS), can modulate memory processes, specifically extinction memory, is an area of active investigation for improving therapeutic outcomes in PTSD.
Trial design
This completed study, designated as Phase NA, enrolled 62 participants with PTSD. The trial investigated the effects of transcranial direct current stimulation (tDCS) timing on extinction memory. Participants were randomized into three groups: one receiving active tDCS during extinction learning followed by sham during consolidation, another receiving sham during extinction followed by active tDCS during consolidation, and a third group receiving sham stimulation during both extinction and consolidation. The study also included an online sub-study focused on contextual processing.
Key results
The trial reported key measurements related to skin conductance responses, a physiological indicator often used in studies of fear and safety memory. During extinction recall, the mean skin conductance in microsiemens for the groups were:
- For the group receiving active tDCS during extinction learning followed by sham tDCS during consolidation: a mean of 0.075 (Standard Error 0.025).
- For the group receiving sham tDCS during extinction followed by active tDCS during consolidation: a mean of 0.088 (Standard Error 0.026).
- For the group receiving sham tDCS during extinction followed by sham tDCS during consolidation: a mean of 0.057 (Standard Error 0.025).
A Mixed Models Analysis comparing the three groups on skin conductance reactivity to the previously extinguished stimulus versus the never conditioned stimulus during extinction recall yielded a p-value of 0.02.
What this means
The statistically significant p-value of 0.02 from the Mixed Models Analysis suggests that the timing of tDCS application, either during extinction learning or consolidation, had a differential effect on skin conductance reactivity during extinction recall in individuals with PTSD. These findings indicate that modulating brain activity with tDCS at specific time points could influence physiological markers related to safety memory. Further research would be needed to understand the clinical implications of these physiological changes and whether they translate into improved PTSD symptoms.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT04152772, titled "Effect of tDCS Timing on Safety Memory in PTSD", were posted on 2025-10-21 on clinicaltrials.gov.