Does non-invasive brain stimulation modulate emotional stress reactivity?

Area of Science:

• Neuroscience
• Psychology
• Psychiatry

Background:

• Excessive emotional responses to stress impair psychological functioning and mental health.
• Non-invasive brain stimulation (NBS) targeting the prefrontal cortex (PFC) may regulate stress-related emotional responses.
• Systematic analysis of NBS reliability and effect sizes on emotional reactivity is lacking.

Purpose of the Study:

• To meta-analyze the effects of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) over the PFC on acute emotional stress reactivity in healthy individuals.
• To assess the reliability and effect sizes of NBS interventions for stress-related emotional responses.

Main Methods:

• Meta-analysis of 40 sham-controlled, single-session rTMS and tDCS studies targeting the PFC.
• Random effects models were used to estimate mean effect sizes for emotional reactivity.
• Studies included healthy individuals exposed to acute emotional stress.

Main Results:

• Twelve rTMS studies found no significant evidence of PFC rTMS influencing emotional reactivity.
• Twenty-six anodal tDCS studies indicated a weak beneficial effect on stress-related emotional reactivity (Hedges' g = -0.16).
• Single-session NBS interventions did not yield reliable, clinically significant effects.

Conclusions:

• Current single-session NBS protocols targeting the PFC appear insufficient for reliable clinical impact on acute stress reactivity.
• Preliminary evidence suggests specific NBS methods, like tDCS, can modulate emotional reactivity.
• Findings may guide future research to enhance NBS efficacy for stress-related psychological processes.