Intrusive Memories found more commonly during 3rd week of Menstrual cycle

Dr Sunjeev Kamboj

Lecturer in Clinical Psychology
Co-ordinator for International DClinPsy Trainees What are the main findings of the study?

Dr. Kamboj: Using a fairly standard approach for this type of research, we measured the frequency of intrusive memories in normal, healthy women after they watched a series of video clips containing distressing scenes. We also measured baseline levels of progesterone and estrogen. We tested three groups of women who, while similar in all respects such age, education level, as well as how they responded to the film, differed in terms of the stage of the menstrual cycle they were in.

Our key finding was that women in the ‘early luteal phase’ – which occurs in the third week of the cycle – had three times as many intrusive memories about the video than women in the first two weeks or fourth week of the cycle. Were any of the findings unexpected?

Dr. Kamboj: Women who do not use the contraceptive pill (similar hormone-based contraceptives), experience normal fluctuations in progesterone and estrogen levels throughout the menstrual cycle. Some research suggests that hormonal changes cause monthly changes in some women’s mood and physical symptoms and these tend to be most prominent in the last (fourth) week of the cycle. We also have some data to suggest that important emotion-related changes occur in the forth week of the cycle. So we would have been less surprised to see higher levels of intrusions in the fourth week of the cycle rather than the third week. In addition, the higher level of intrusions in the third week occurred without any self-reported changes in anxiety or pre-menstrual symptoms suggesting that the effect is due to mood-independent effects on memory. Of course, this work needs to be replicated and extended to examine these ideas more carefully. What should clinicians and patients take away from your report?

Dr. Kamboj:  It is really important to bear in mind that our study was done with healthy, young women (18-35 years old) who were not using hormone-based contraceptives. So while this seems to be a normal response to stressful events in these women, we still don’t know how ‘the average women’ would respond to this type of stress. For example, older women might respond differently, particularly those who have been through the menopause, which involves major changes in hormone levels. We also don’t know how women who use the contraceptive pill or other hormone based contraceptives would respond. Clearly these are important areas of future research as they may give us important clues about how natural and artificially-induced changes in hormones affect this process. What recommendations do you have for future research as a result of this study?

Dr. Kamboj:  The most important follow-up research will be in clinical samples. For example, if we were to examine hormone levels and intrusive memories (one of the main symptom of traumatic stress disorders) in women who attend emergency rooms after an accident in a naturalistic experiment, we would have a clearer idea of the clinical relevance of these findings. This kind of experiment would also allow us to determine the effects of things like age and whether the contraceptive pill has an effect on these symptoms.


Identification of a narrow post-ovulatory window of vulnerability to distressing involuntary memories in healthy women

Soni M, Curran VH, Kamboj SK.

Clinical Psychopharmacology Unit, Research Department of Clinical, Educational and Health Psychology, University College London, Gower Street, London WC1E 6BT, United Kingdom.

Neurobiol Learn Mem. 2013 Apr 21;104C:32-38. doi: 10.1016/j.nlm.2013.04.003.
[Epub ahead of print]

Last Updated on June 4, 2013 by Marie Benz MD FAAD