Are traumatic memories at first extraordinarily bad and then extraordinarily good?

Abstract

Mazzoni et al. (2025) seek to reach a middle ground in which they cite research purporting that traumatic memory can be special, yet noting the conceptual creep of the concept of trauma, and by suggesting an openness to further research. Mazzoni et al. point out that negative events might enhance memory sometimes (e.g. Berntsen & Rubin, 2014), and might impair memory sometimes (e.g. Roth et al., 2011). We concur that on the one hand a shocking event is likely to be consolidated more strongly than neutral events, and that chronic and prolonged stress can damage the functioning of the hippocampus and impair memory. This is a decent middle ground. We suppose that in these narrow senses traumatic memory can be special. This is nuanced as noted in Mazzoni et al.—for example traumatic memories are sometimes both strongly consolidated but still inaccurate over time.

Nevertheless, we add the caveat that by ‘special’ we do not mean dissociated or repressed, we just mean sometimes enhanced by epinephrine or sometimes impaired by stress. Notice that in the controversial concept of dissociative amnesia, the ‘special’ status is making a much bolder claim. It is proposed that there is a period of extraordinarily poor memory (zero in fact), followed by extraordinarily good memory. So good, in fact, that the memories arising out of dissociative amnesia might be so trustworthy to be used in legal cases (of course, we disagree, but this is the claim). It is this combination of terrible memory followed by extraordinary memory, caused by psychogenic mechanisms, that we object to.

There is one concern that if we do not get the terminology exactly correct about DNA methylation studies, that inexactness may spread through the pseudoscientific world of therapies that justify attempting to recover traumatic memories. Mazzoni et al. state that ‘chronic psychosocial stress changes the DNA of a gene in the hippocampus’, and that seems wrong. DNA methylation can suppress gene transcription but it does not change the DNA or the individual genes (see Moore et al., 2013). In effect, the stress in these experiments seem to be affecting the transcription of proteins that the genes would otherwise produce without the stress. Proteins produced by genes in hippocampal neurons (and in connected networks) are needed in both long-term potentiation (see Patihis, 2018) and in dendrite growth (Del Blanco et al., 2019), so it makes sense that chronic stress that blocks transcription would impair memory formation.

Mazzoni et al. (2025) informs us not only of the terrible Bibbiano scandal in Italy—in which many lives were changed by false memories produced by the therapists—but also that the problems may not be over. If it is true that a large majority of clinicians have received education in the Bessel van der Kolk approach, there may be many false accusations in the future in Italy. Van der Kolk's idea that traumas may resurface as sensations in the body can be used as a terrible starting point in therapy for memory construction.

In summary, the middle ground we have found with Mazzoni et al. (2025) is that negative events can be enhanced sometimes, sometimes impaired, depending on the type of event and that we have an open mind into future research into both of these areas.