Modulation of fear extinction by non-invasive brain stimulation:
systematic review and meta-analysis
Abstract
Non-invasive brain stimulation (NIBS) is an emerging treatment for
mental disorders that is painlessness and easy to administer. However,
its effectiveness for treating fear extinction requires further
elucidation. We searched eight bibliographical databases and identified
randomized controlled trials of NIBS interventions for fear extinction
in healthy populations. Outcomes were evaluated based on skin
conductance response (SCR) under three experimental conditions: threat
condition stimulation (CS+), safe condition stimulation (CS−), and their
discrimination (CS+ minus CS−). We applied a random-effects model to
determine effect sizes (Hedge’s g) post-intervention and assessed
article quality using Physiotherapy evidence database (PEDro) scale.
Twenty-one studies meeting systematic review criteria were included in
this analysis, incorporating 40 independent effect sizes and data from
11 studies (n = 632) in the meta-analysis. Compared with the control
group, the intervention group exhibited significant reductions SCRs: CS+
(g = −0.32, 95% confidence interval (CI) [−0.56, −0.07]) and
discrimination (g = −0.35; 95% CI [−0.55, −0.15]). Fear extinction
was more effective in the 24-hour test than immediately after NIBS. In
conclusion, NIBS enhanced fear extinction, and the time interval between
stimulus and testing may serve as a moderating variable.