An alternative theory for hormone effects on sex differences in PTSD: The role of heightened sex hormones during trauma

• Published in: Psychoneuroendocrinology 2019-11, Vol.109, p.104416-104416, Article 104416
• Main Authors: Ney, Luke John, Gogos, Andrea, Ken Hsu, Chia-Ming, Felmingham, Kim Louise
• Format: Article
• Language: English
• Subjects: Emotional memory; Memory consolidation; Posttraumatic stress disorder; Sex differences; Sex hormones; Stress hormones
• ISSN: 0306-4530; 1873-3360
• DOI: 10.1016/j.psyneuen.2019.104416

•Sex differences in PTSD are a prominent yet poorly understood phenomenon.•Sex hormones, particularly progesterone, are precursors of stress hormones.•Progesterone and oestradiol can also enhance memory consolidation of emotional experiences.•We propose that high levels of progesterone and oestradiol during trauma are a likely cause of sex differences in PTSD.•Reframing sex differences in PTSD has implications for our current understanding as well as how treatments may be managed. Women are at least twice as susceptible to developing post-traumatic stress disorder (PTSD) compared to men. Although most research seeking to explain this discrepancy has focussed on the role of oestradiol during fear extinction learning, the role of progesterone has been overlooked, despite relatively consistent findings being reported concerning the role of progesterone during consolidation of emotional and intrusive memories. In this review article, we outline literature supporting the role of progesterone on memory formation, with particular emphasis on potential memory-enhancing properties of progesterone when subjects are placed under stress. It is possible that progesterone directly and indirectly exerts memory-enhancing effects at the time of trauma, which is an effect that may not be necessarily captured during non-stressful paradigms. We propose a model whereby progesterone’s steroidogenic relationship to cortisol and brain-derived neurotrophic factor in combination with elevated oestradiol may enhance emotional memory consolidation during trauma and therefore present a specific vulnerability to PTSD formation in women, particularly during the mid-luteal phase of the menstrual cycle.