Author's response to reviews Title:Subjective Memory Complaints and Memory Performance in Patients with Borderline Personality Disorder Authors: Thomas Beblo (thomas.beblo@evkb.de) Christoph Mensebach (mensebach@web.de) Katja Wingenfeld (Katja.Wingenfeld@charite.de) Nina Rullkoetter (nrullkoetter@yahoo.de) Nicole Schlosser (nicole.schlosser@evkb.de) Martin Driessen (martin.driessen@evkb.de) Version:2Date:16 June 2014 Author's response to reviews: see over
Ev. Krankenhaus Bielefeld ggmbh Postfach 130360 D-33546 Bielefeld Re-Submission 2251492791213342 Klinik für Psychiatrie und Psychotherapie Bethel Chefarzt: Prof. Dr. Martin Driessen Remterweg 69/71 33617 Bielefeld Information Telefon 0521 I 772-77115 Abteilung für Forschung Leitung: Prof. Dr. rer. nat. Thomas Beblo Telefon 0521 772-78512 Telefax 0521 772-78511 E-Mail thomas.beblo@evkb.de Internet www.psychiatrie-forschungbethel.de Akademisches Lehrkrankenhaus der Universität Münster Sitz der Gesellschaft Kantensiek 11 33617 Bielefeld Sparkasse Bielefeld BLZ 48050161 Kto. 6429658 Amtsgericht Bielefeld HRB 30169 Geschäftsführer Dr. Rainer Norden Vorsitzender des Aufsichtsrates Pastor Ulrich Pohl Dear Dr. Chua, June, 12, 2014 Thank you for your e-mail from May, 6, 2014. We were pleased to get the opportunity to revise our manuscript 2251492791213342 Subjective Memory Complaints and Memory Performance in Patients with Borderline Personality Disorder. We appreciate yours and the reviewers constructive suggestions and found that they helped us to improve our manuscript As you see in the detailed point-by-point reply, all recommendations have been incorporated into the manuscript. Please don t hesitate to contact me if you have any questions or if there are still problems that need to be addressed. We hope that the manuscript in its present form is acceptable for BMC Psychiatry! Sincerely yours, Thomas Beblo, PhD (for all authors) Clinic for Psychiatry and Psychotherapy Bethel, Ev. Hospital Bielefeld Remterweg 69-71 33617 Bielefeld, Germany Tel.: 0049 / 521 / 772-78512, Fax: 0049 / 521 / 772-78511, e-mail: thomas.beblo@evkb.de
2 Editor 1. The major issue with this paper is the lack of an adequate relevance given to the problem of validity of subjective memory complains vs. the one of objective memory complains. There is a continuous scientific production on this topic, even though it is not only recent. We agree that validity of subjective measures is a problem in this field of research. However, as many BPD patients seem to be handicapped by these problems in their everyday life it is important to investigate this topic. With standardized neuropsychological tests only, different challenges of everyday life cannot be assessed. E.g. situations in everyday life are often more complex than neuropsychological tests and these situations provide emotional distracters that are absent in test settings. In addition, patients get motivated and if necessary structured by the examiner in neuropsychological test settings but not in everyday life. For these reasons, everyday life cognitive functioning should be examined by other paradigms than tests as well. Apart from questionnaires, however, so far no other standardized paradigms have been developed to assess everyday life cognitive functions. In addition, despite doubts about the validity of questionnaires, some studies clearly support their validity. E.g. van der Flier et al. (2004) and Stewart et al. (2011) showed subjective memory complaints to be related to neuroimaging results (page 3, paragraph 2). In particular, the here used Everyday Memory Questionnaire (EMQ) has been acknowledged for its validity. E.g. Garrett et al. (2010, Everyday memory compensation: The impact of cognitive reserve, subjective memory, and stress, Psychology and Aging, 25, 74-83) wrote The EMQ has been employed in several previous studies of older adults (e.g., Efklides et al., 2002; Koltai, Bowler, & Shore, 1996; Neupert et al., 2006), and unlike many other memory complaint scales (see Hertzog, Park, Morrell, & Martin, 2000; Pearman & Storandt, 2004), it correlates with several different objective memory measures (e.g., Efklides et al., 2002; Koltai et al., 1996; Neupert et al., 2006). We therefore decided (a) to include tests and a validated questionnaire (the EMQ), and (b) to profoundly discuss the problem of validity in our paper including the Garrett paper (page 13, paragraph 2). 2. The other issue is due to the fact that you consider your analysis demonstrative that the subjective memory complains are not related to the anxiety and depression difficulties of your patients, once the contribution of BPD symptoms is removed. I would suggest that you discuss the possibility that this in fact, demonstrates that emotional control problems are the common
3 matrix of both anxiety symptoms and BPD symptoms and hence, each source has the legitimacy to be considered separately related to the subjective memory disorders. Corresponding to your suggestion, we modified paragraph 1 on page 11. We added However, SMC may be related to commonalities among these disorders such as emotion regulation difficulties. However, we are not sure whether we fully understand your comment. Please let us know if we did not meet your concern. 3. Finally, since you cannot present comparative analysis of BPD patients vs. others of different clinical groups it is very difficult to accept that the evidence on which you base your statement is sufficient to present this clinical picture as specific and limited to BPD patients. As subjective memory complaints have not been investigated in BPD patients so far, we aimed at confirming those complaints in BPD with this first study in the field. In addition and more importantly, our research questions and the (clinical) relevance of our results are not related to its possible specificity: Our results indicate that BPD patients may suffer from cognitive impairments in everyday life even when neuropsychological tests results are normal - independent of the question whether patients with other mental disorders present this pattern as well. Therefore, we conclude that neuropsychological assessment of BPD patients should include the administration of respective questionnaires. Furthermore, we conclude that the complaints about cognitive dysfunction may be considered as diagnostic criteria for BPD (page 13, paragraph 1). Again, this conclusion does not depend on the specificity of our findings. By contrast, we came to this conclusion because such complaints are diagnostic criteria in other mental disorders such as MDD. Reviewer 1: Dear Professor Landro, Thank you for taking time reviewing our manuscript 2251492791213342 Subjective Memory Complaints and Memory Performance in Patients with Borderline Personality Disorder. We appreciate your constructive suggestions and found that they helped us improve our manuscript. As you see in the detailed point-by-point reply, we carried out three different analyses to pursue your first recommendation and followed your second recommendation.
4 4. Looking at the EMQ it obviously contains items covering a broad range of cognitive functions, like concentration/attention, absentmindedness, route finding, face recognition in addition to phenomena more directly reflecting memory. As far as I know factor analyses have also shown that an independent attention factor as well as a memory factor show up in many studies (see for example Royle & Lincoln, 2008). I suggest the authors look into the literature and consider if they could re-analyse their data taking such a more nuanced factor into account. A possible alternative hypothesis would be that BPD patients complaints are more related to attention and other executive functions than memory as such. We agree that the EMQ possibly contains items covering different functional domains. With the EMQ, Sunderland et al. (1983 and 1984) aimed at considering different memory related situations. E.g. some situations are rather related to the verbal domain (such as word finding problems) others to the nonverbal domain (such as getting lost). We therefore also included verbal and nonverbal memory tests in our study. Based on a principal component analyses, nevertheless, Sunderland et al. (1984) suggest that the EMQ reflects everyday memory in general. It is true that newer paper claim different factors underlying the EMQ but these papers are hard to compare given that different EMQ versions were administered. In addition, methodology of some paper is limited. E.g. Royle and Lincoln (2008) restrict their analyses on exploratory PCAs and they do not consider exterior criteria to validate the factors. Regardless of the EMQ factor structure, it is clear that memory is not independent of other neuropsychological domains such as attention and executive functions. Like the EMQ score, memory test performance depends on these underlying functions, too. Because we had no (a priori) hypotheses with respect to these underlying functions, we restricted our analyses to the EMQ total score and (the total scores of) the memory tests. However, your suggestion to analyze the EMQ data in a more sophisticated way is appealing. We pursued your idea by three different strategies: 1. We were looking for group differences with respect to the retrieval items vs attention items proposed by Royle & Lincoln (2008): BPD patients and healthy controls differed significantly with respect of all retrieval items (5, 6, 8, 13, 14, 15, 18) and all attention items (16, 17, 20, 28). Furthermore, the means of the respective effect sizes were equal: d (retrieval) = 1.3, d (attention) = 1.3. Thus, BPD patients complaints are indeed related to memory and our data do not indicate that their complaints are more related to attention.
5 2. With only one exception (item 11), groups differed significantly with respect to all EMQ items (all p <.020) indicating that BPD patients complaints affect all potential subfunctions as assessed with the EMQ. 3. We performed exploratory factor analyses. Results of an exploratory principal component analyses indicate a general factor with 40% explained variance in the BPD sample and factor loadings >.5 for all items but five (items 5, 9, 10, 11, 27). However, even these five items show loadings >.3. This analysis does not support the notion of strictly distinguishable EMQ subfunctions. Of course, sizes of our samples are very small. Thus, results of factor analyses have to be considered as highly preliminary. Given that we had no a priori hypotheses with respect to EMQ subfunctions, we did not include these exploratory analyses in our manuscript. Furthermore, if we would put these analyses and research questions into the manuscript, further questions would arise, e.g. whether the results of the memory tests applied were related to underlying subfunctions as well. Please let us know if you come to other conclusions based on our exploratory analyses presented here. 5. Quality of written English: Needs some language corrections before being published. The article has now been corrected by an professional proof-reader (and native speaker). Reviewer 2: Dear Dr. Niedtfeld, Thank you for taking time reviewing our manuscript 2251492791213342 Subjective Memory Complaints and Memory Performance in Patients with Borderline Personality Disorder. We appreciate your constructive suggestions and found that they helped us improve our manuscript. As you see in the detailed point-by-point reply, all of your recommendations have been incorporated into the manuscript. 6. This is a well-written manuscript presenting interesting data on the relation of subjective memory impairments with borderline psychopathology. The study design is straightforward and the interpretation of the results is adequate. We are pleased about this appreciation.
6 7. Please provide a reference for the statement: "A mean BSL-score of 161 for the BPD patients indicates a moderate manifestation of BPD-related symptoms." We now provide a reference for our statement (page 6, paragraph 2): Bohus M, Limberger MF, Frank U, Sender I, Gratwohl T, Stieglitz R-D: Entwicklung der Borderline- Symptom- Liste. Psychother Psych Med 2001, 51:201-211. 8. Since statistical significance is heavily dependent upon sample size, it would be useful for the interpretation of the results to report effect sizes (i.e., Cohens d) for the non-significant results in table 1. Since all of the effect sizes are small (d=0 for Logical Memory 1&2, d=.20 for AVLT, d=.32 for CFT, d=.14 for RVDLT), the authors could thereby strengthen their discussion. We included the effect sizes of all measures in table 1 (Cohens d). We also included respective comments in the results section (page 9, paragraph 1 and paragraph 2). We agree that this information strengthen the notion of normal test results in the discussion section (page 10, paragraph 3). 9. Please describe the Everyday Memory Questionnaire in more detail (i.e. example item) and provide information about the phrasing of the items (does the answer "yes" always point to memory impairments?). Since BPD patients are known to show answering biases, it would be an important limitation of the study if all items of the EMQ were positively phrased, because this implies that the significant difference between BPD patients and healthy controls in SMC may be caused by answering biases (i.e., acquiescence bias). We have now described the EMQ much more in detail (page 7, paragraph 3).We now also provide information about the items phrasing: The items do not require yes or no answers but ratings from 1 (not at all problems in the last six months to 9 (problems more than once a day). Nevertheless, we agree that the uniform polarization of the items is a limitation of the questionnaire. We have now added this fact in the discussion (page 13, paragraph 2). However, for the study we decided for the EMQ as the EMQ has been broadly acknowledged for its validity (E.g. Garrett et al. (2010, Everyday memory compensation: The impact of cognitive reserve, subjective memory, and stress, Psychology and Aging, 25, 74-83).
7 10. Although not investigated within this study, I think the possible influence of co-morbid ADHD on everyday memory difficulties in BPD could also be addressed in the discussion. We now discuss the possible influence of comorbid ADHD in the discussion section (page 14, paragraph 1) as a limitation of the study results.