# Effect of tDCS timing on safety memory in PTSD

> **NIH NIH P20** · BUTLER HOSPITAL (PROVIDENCE, RI) · 2021 · $358,571

## Abstract

PROJECT SUMMARY/ABSTRACT
Posttraumatic stress disorder (PTSD) is the 5th most prevalent mental disorder in the USA. The gold-standard
treatment for PTSD includes exposure-based therapy, which relies on adequate extinction processes to be
successful in reducing symptoms. Although the efficacy of exposure therapy is scientifically established, many
patients do not satisfactorily benefit and symptomatic relapse following treatment is common. Therefore, there
is a pressing need to identify effective novel options to improve the effectiveness of exposure therapy for PTSD
treatment. A laboratory analogue for exposure-based therapy is the extinction of conditioned fear, often
designated as “extinction learning”. The goal of extinction, in the clinic and research laboratory, is to form new
safety memories that can be recalled in order to inhibit fear responses associated with the original trauma. The
ability to remember new safety memories after extinction is termed “extinction retention”. Adequate extinction
learning and retention is supported by the ventromedial prefrontal cortex (VMPFC), signifying “top-down”
prefrontal regulation of fear expression. Abnormalities in VMPFC functioning and extinction retention are
extensively associated with PTSD. Accordingly, our group piloted the use of noninvasive transcranial direct
current stimulation (tDCS) to facilitate VMPFC function during extinction in a Pavlovian fear conditioning
paradigm. Preliminary results suggests that tDCS could enhance extinction retention, but this effect appears to
depend on the timing of stimulation in relation to extinction learning. Specifically, our preliminary evidence
suggests tDCS after extinction learning might have stronger effects on extinction retention versus stimulation
during extinction learning. An essential next step is to determine the effect of timing of VMPFC-targeted tDCS,
and thus whether tDCS during or immediately following extinction learning more effectively enhances extinction
retention in individuals with PTSD. This will provide critical knowledge on the optimal, i.e. most effective, tDCS
timing protocol to enhance extinction memory fundamental to successful exposure-based treatment. Results of
the proposed research will directly inform further development of clinical trials aimed to test the application of
tDCS to enhance exposure-based therapeutic interventions for PTSD. The current COBRE proposal will use a
well-established fear-conditioning paradigm to systematically test how tDCS timing in relation to extinction
learning affects physiological arousal (skin conductance responses) and associated neural responses using
neuroimaging at time of extinction retention.

## Key facts

- **NIH application ID:** 10106651
- **Project number:** 5P20GM130452-03
- **Recipient organization:** BUTLER HOSPITAL (PROVIDENCE, RI)
- **Principal Investigator:** Mascha van 't Wout-Frank
- **Activity code:** P20 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $358,571
- **Award type:** 5
- **Project period:** 2019-03-01 → 2024-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10106651

## Citation

> US National Institutes of Health, RePORTER application 10106651, Effect of tDCS timing on safety memory in PTSD (5P20GM130452-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10106651. Licensed CC0.

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