RE: Post-traumatic Stress as the Primary Cause for Cognitive Decline—Not the Whole Story, and Perhaps No Story at All
JNCI J Natl Cancer Inst (
RE: Post-traumatic Stress as the Primary Cause for Cognitive Decline-Not the Whole Story, and Perhaps No Story at All
Kerstin Hermelink 0 1
Markus Bu¨ hner 0 1
Karin Mu¨ nzel 0 1
Sven Mahner 0 1
Nadia Harbeck 0 1
0 The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions , please
1 Affiliations of authors: Breast Center, Department of Gynecology and Obstetrics, CCCLMU University Hospital of Munich , Munich, Germany (KH, SM , NH); Department of Psychology, Division of Psychological Methods and Assessment, Ludwig Maximilian University of Munich , Munich , Germany ( MB); Department of Psychology, Division of Neuropsychology, Ludwig Maximilian University of Munich , Munich, Germany, KM
We would like to comment on the editorial (
our recent article in the Journal, written by our esteemed
colleagues Sanne B. Schagen and Jeffrey S. Wefel. We welcome
the opportunity to discuss some issues raised in the editorial
regarding both the current and previous studies from our
) that we feel need clarification and further
We are strongly criticized for combining commission errors
and omission errors on the Go/Nogo test—according to the
editorialists, “both secondary outcomes measuring errors on a
reaction time test”—in a Go/Nogo error score. We wish to point
out that commission errors and omission errors are not
secondary but primary outcomes of the Go/Nogo, a test of
), and that the exact score used in our analyses—
combined commission and omission errors on the Go/Nogo test
of the Testbatterie zur Aufmerksamkeitspr u¨fung (TAP) (
validated in German breast cancer patients (
). As an aside, the
literature on cancer-related cognitive dysfunction is full of
combined scores like domain-specific and overall cognitive
function scores, for understandable reasons, and we used an
overall score ourselves. Between studies, there is considerable
variation in the composition of measures that go into these
scores, and the vast majority of them have never been
The editorialists allege that we created a variable “termed
‘degree of PTSD.’” This obscure term is quoted six times in
the editorial although it does not appear in either of our
articles. The variable that was used to measure the burden
of post-traumatic stress was (number of) PTSD symptoms.
As correctly stated in the editorial, PTSD symptoms were
assessed with clinical diagnostics based on a validated
). Contrary to the editorialists’ claims, the interview
is suited to diagnose symptoms, as stated in its manual:
“The Structured Clinical Interview for DSM-IV (SCID) is
a semi-structured clinical interview to assess symptoms,
syndromes, and diagnoses” (page 4, translation by K.
Hermelink). We would further like to note that the stopping
rules, which we disregarded to allow a full assessment of
PTSD symptoms, do not contribute to the interview’s
validity but are intended to save time if the interviewer is
interested in diagnoses.
We are accused of ignoring that in our study “overall
cognitive decline is not mediated by PTSD.” In fact, we saw mediation
of overall cognitive change by PTSD symptoms (effect of cancer
without mediation, P ¼ .04; with mediation, P ¼ .07), but the
mediation effect was not statistically significant (bootstrapped 95%
confidence interval ¼ –0.06 to 0.03), probably because of a lack
of power. We did observe and report statistically significant
bivariate associations of age- and education-corrected overall
cognitive change at T3 with PTSD symptoms at T3 as well as T2
(P ¼ .001 and P ¼ .002, respectively).
Finally, the editorialists’ statement that “Hermelink et al.
start out. . .asserting that it is very ‘unlikely that (PTSD) does not
impact the brain’” is a misquotation. The sentence reads, “It
seems very unlikely that distress, sleep problems, and
prolonged sick leave, among other factors associated with having
cancer, do not impact the brain” (
1. Schagen SB , Wefel JS . Post-traumatic stress as the primary cause for cognitive decline-not the whole story, and perhaps no story at all . J Natl Cancer Inst . 2017 ; 109 ( 10 ): djx091 .
2. Hermelink K , Bu¨ hner M, Sckopke P , et al. Chemotherapy and post-traumatic stress in the causation of cognitive dysfunction in breast cancer patients . J Natl Cancer Inst . 2017 ; 109 ( 10 ): djx057 .
3. Hermelink K , Voigt V , Kaste J , et al. Elucidating pretreatment cognitive impairment in breast cancer patients: The impact of cancer-related post-traumatic stress . J Natl Cancer Inst . 2015 ; 107 ( 7 ): djv099 .
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5. Zimmermann P , Fimm B . Testbatterie zur Aufmerksamkeitspr u¨fung (TAP) . Version 2 .2 [Tests of Attentional Performance]. Herzogenrath, Germany: Psytest; 2009 .
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7. Wittchen H , Zaudig M , Fydrich T. SKID . Strukturiertes Klinisches Interview f u¨r DSM-IV. Achse I und II . Handanweisung. Go¨ ttingen, Germany: Hogrefe; 1997 .