Targeting active forgetting with non-invasive stimulation: toward novel treatments for intrusive memories in PTSD.

PTSD is characterized by persistent and intrusive recollections of traumatic events, often due to the failure of natural forgetting processes. Recent neuroscientific advances have identified active forgetting as a dynamic and regulated process involving specific brain circuits and molecular pathways, particularly within the hippocampus and prefrontal cortex. By leveraging targeted neurostimulation methods, such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), transcranial ultrasound stimulation (TUS), or peripheral nerve stimulation, we explore how modulating these circuits may enhance adaptive forgetting and reduce pathological memory persistence. This review aims to: (1) map the neural correlates of active forgetting in individuals with PTSD; (2) explore the neurotransmitters implicated in active forgetting; (3) review the research on non-invasive neurostimulation aimed at enhancing forgetting of maladaptive memories; and (4) identify outstanding questions and future directions of such interventions. By bridging cognitive neuroscience, clinical psychology, and neurotechnology, this work seeks to establish a novel framework for PTSD treatment that moves beyond symptom management to address the core memory mechanisms underlying the disorder.