Electroconvulsive Therapy and Posttraumatic Stress Disorder: First Experience With Conversation-Based Reactivation of Traumatic Memory Contents and Subsequent ECT-Mediated Impairment of Reconsolidation.

Mappe: ECT/2014 a

2014

Maximilian Gahr, M.D.

Carlos Schönfeldt-Lecuona, M.D. Manfred Spitzer, M.D.

Heiko Graf, M.D.

Dept. of Psychiatry and Psychotherapy III, University Hospital of Ulm, Ulm, Germany

To the Editor: Strong and recurrent activation of traumatic memory contents (TMC) was suggested to be an essential pathophysiologic mechanism in posttraumatic stress disorder (PTSD). 1 Thus, reduced activation or availability of this particular TMC could result in amelioration of PTSD core symptoms.

Recently demonstrated efficacy of ECT in the treatment of PTSD 3 might be due to impaired reactivation of TMC. Consolidated memory contents are suggested to be destabilized during their retrieval, and thus, sensitive for modifications at the time of their current recall and reconsolidation. 4 Hence, ECT might be most effective immediately after an active (conversation-based) confrontation with the TMC

a conversation-based reactivation of this particular TMC was performed immediately before ECT (duration of 10 minutes). The patient was advised to remember the accident and to describe his particular memories verbally (average time between end of memory reactivation and application of etomidate: 10 minutes)

The patient reported improvement of PTSDsymptoms accompanied by a more clear improvement of depression. PTSD-symptoms related to the accident subsided completely and though PTSD-symptoms persisted, they were not accompanied by memories related to the accident.

Evidence for the possible efficacy of ECT in the treatment of therapy-refractory PTSD by specific elimination of one particular TMC. However, PTSD symptoms did not subside completely. This is partly explained by the fact that the patient´s PTSD was due to multiple traumas.

Preventing the return of fear in humans using reconsolidation update mechanisms

Mappe: Authors/Schiller

Daniela Schiller 1,2 , Marie-H. Monfils 1,3 , Candace M. Raio 2 , David C. Johnson 2 , Joseph E. LeDoux 1 & Elizabeth A. Phelps 1,2

Recent research on changing fears has examined targeting reconsolidation. During reconsolidation, stored information is rendered labile after being retrieved. Pharmacological manipulations at this stage result in an inability to retrieve the memories at later times, suggesting that they are erased or persistently inhibited. Unfortunately, the use of these pharmacological manipulations in humans can be problematic. Here we introduce a non-invasive technique to target the reconsolidation of fear memories in humans. We provide evidence that old fear memories can be updated with non-fearful information provided during the reconsolidation window. As a consequence, fear responses are no longer expressed, an effect that lasted at least a year and was selective only to reactivated memories without affecting others. These findings demonstrate the adaptive role of reconsolidation as a window of opportunity to rewrite emotional memories, and suggest a non-invasive technique that can be used safely in humans to prevent the return of fear.

Reconsolidation of Human Memory: Brain Mechanisms and Clinical Relevance

Mappe: authors/Karim Nader 2014 a

Lars Schwabe, Karim Nader, and Jens C. Pruessner

The processes of memory formation and storage are complex and highly dynamic. Once memories are consolidated, they are not necessarily fixed but can be changed long after storage. In particular, seemingly stable memories may re-enter an unstable state when they are retrieved, from which they must be re-stabilized during a process known as reconsolidation. During reconsolidation, memories are susceptible to modifications again, thus providing an opportunity to update seemingly stable memories. While initial demonstrations of memory reconsolidation came mainly from animal studies, evidence for reconsolidation in humans is now accumulating as well. Here, we review recent advances in our understanding of human memory reconsolidation. After a summary of findings on the reconsolidation of human fear and episodic memory, we focus particularly on recent neuroimaging data that provide first insights into how reconsolidation processes are implemented in the human brain. Finally, we discuss the implications of memory modifications during reconsolidation for the treatment of mental disorders such as posttraumatic stress disorder and drug addiction.