The Nature of Traumatic Memories

To the Editor: Ruth A. Lanius, M.D., Ph.D., et al. (1) claimed that the differences they found in brain connectivity between subjects with posttraumatic stress disorder (PTSD) and comparison subjects “may account for the nonverbal nature of traumatic memory recall of PTSD subjects, compared to a more verbal pattern of traumatic memory recall in comparison subjects” (p. 36). This statement would seem to imply that there could be a difference between traumatic and other memory. It is questionable, however, whether responses provoked by reading a script to subjects would permit conclusions about “memory” in the usual sense.

Furthermore, the authors reported that the 11 subjects with PTSD collectively had nine comorbid axis I diagnoses and that five had current nicotine abuse, while their comparison subjects had no such conditions. The authors’ failure to control for this factor in their analysis suggests strongly that their conclusions are not legitimate with respect to memory. The predominance of differences in frontal and limbic regions makes it seem far more likely that their results reflect differences in emotional arousal, which is not surprising given the axis I characteristics of their PTSD subjects. Such responses hardly constitute proof of a difference in memory.