Oxytocin vs. placebo effects on intrusive memory consolidation using a trauma film paradigm: a randomized, controlled experimental study in healthy women

Abstract

Oxytocin administration during a trauma analogue has been shown to increase intrusive memories, which are a core symptom of post-traumatic stress disorder (PTSD). However, it is unknown whether oxytocin influences the acquisition or the consolidation of the trauma. The current study investigates the effect of the activation of the oxytocin system during the consolidation of an analogue trauma on the formation of intrusive memories over four consecutive days and whether this effect is influenced by individual neurobiological, genetic, or psychological factors. We conducted a randomized double-blind placebo-controlled study in 217 healthy women. They received either a single dose of intranasal oxytocin (24 IU) or placebo after exposure to a trauma film paradigm, which reliably induces intrusive memories. We used a general random forest to examine a potential heterogeneous treatment effect of oxytocin on the consolidation of intrusive memories. Furthermore, we used a poisson regression to examine whether salivary alpha amylase activity (sAA) as a marker of noradrenergic activity and cortisol response to the film, polygenic risk score (PRS) for psychiatric disorders, and psychological factors influence the number of intrusive memories. We found no significant effect of oxytocin on the formation of intrusive memories (F(2, 543.16) = 0.75, p = 0.51, ηp2 = 0.00) and identified no heterogeneous treatment effect. We replicated previous associations of the PRS for PTSD, sAA and the cortisol response on intrusive memories. We further found a positive association between high trait anxiety and intrusive memories, and a negative association between the emotion regulation strategy reappraisal and intrusive memories. Data of the present study suggest that the consolidation of intrusive memories in women is modulated by genetic, neurobiological and psychological factors, but is not influenced by oxytocin. Trial registration: NCT03875391.

Effects of oral contraceptives on intrusive memories: a secondary analysis of two studies using the trauma film paradigm in healthy women

“…The here analyzed data was collected in two separate studies, with a similar design analyzing the effect of oxytocin on the acquisition (Schultebraucks et al 2021 ) and consolidation (Maslahati et al, 2022 ) of intrusive memories. The difference between the two studies was the timing of oxytocin administration.…”

“…The difference between the two studies was the timing of oxytocin administration. While oxytocin was administered before the trauma film in the first study (Schultebraucks et al, 2021 ), it was administered after the trauma film in the second study (Maslahati et al, 2022 ). Both studies were conducted within one year in the same room, with an identical setup at the Department of Psychiatry and Neurosciences, Campus Benjamin Franklin, Charité – Universitätsmedizin Berlin.…”

“…In case of ongoing distress, participants were offered psychological care. In the second study (Maslahati et al, 2022 ), one participant reported ongoing intrusions and received six counselling sessions with a licensed psychologist. Associated distress and intrusions of the participant disappeared during aftercare.…”

“…For this purpose, we used Chi-square and Student’s t-test or the non-parametric Mann-Whitney-U-test. Group differences were conducted to ensure there were no differences regarding cortisol, sample characteristics, and psychometric variables that have been shown to be associated with intrusion formation (Breslau et al, 1999 ; Maslahati et al, 2022 ): Childhood Trauma Questionnaire (Bernstein & Fink, 1998 ), state-trait anxiety inventory-trait subscale (Spielberger, 1983 ), Beck depression inventory-revised (Beck et al, 1996 ), emotion regulation questionnaire (Abler & Kessler, 2009 ).…”

“…In the current secondary data analysis, we examined the effect of OC intake in healthy women compared to naturally cycling women in the luteal phase on the development of intrusive memories after watching a trauma film. For this purpose, we reanalyzed the dataset of two previously conducted and published studies (Maslahati et al, 2022 ; Schultebraucks et al, 2021 ) investigating the effect of oxytocin on the acquisition and consolidation of intrusive memories. As low levels of estradiol have been associated with enhanced memory consolidation and OCs result in reduced levels of estradiol, we hypothesized an increased number of intrusive memories in women using OCs compared to naturally cycling women (in the luteal phase) in the following four days after watching a trauma film paradigm.…”