Sex/Gender Differences in Risk and Resilience to PTSD; Implication of Oxytocin

Phase 2

Completed

Brief Summary: The purpose of the study is to use fMRI to investigate amygdala response to fearful faces in men and women with and without PTSD who have experienced childhood trauma. The study will also compare the effects of oxytocin and placebo on amygdala response, and explore the interaction of oxytocin plasma levels and amygdala response in men and women with and without PTSD who have experienced childhood trauma.

Hypothesis 1: Amygdala responding will be greater in subjects with PTSD as compared to resilient subjects, and no sex differences in the magnitude of the response will be found.

Hypothesis 2A: In response to OT, women will exhibit a greater reduction in amygdala responding than men.

Hypothesis 2B: In response to OT, women with PTSD will exhibit a greater reduction in amygdala responding compared to women without PTSD.

Hypothesis 3A: Women with PTSD will have lower levels of plasma OT as compared to men with PTSD, and women and men without PTSD.

Hypothesis 3B: Plasma OT levels will be inversely correlated with amygdala responding to fearful faces in women but not in men.

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
PTSD placebo Day 1, Oxytocin Day 2	Placebo	Participants PTSD will self-administer matching placebo (containing all ingredients except OT) at 10:30 a.m. on Day 1 of study procedures, approximately 45-minutes prior the scanning sessions. This dose and timing of administration were selected based on similar fMRI studies (Domes, et al., 2007; Domes, et al., 2010; Kirsch, et al., 2005).
Resilient Placebo Day 1, Oxytocin Day 2	Placebo	Resilient controls will self-administer matching placebo spray at 10:30 a.m. on Day 1 of study procedures, approximately 45-minutes prior the scanning sessions. This dose and timing of administration were selected based on similar fMRI studies (Domes, et al., 2007; Domes, et al., 2010; Kirsch, et al., 2005).
Resilient Oxytocin Day 1, Placebo Day 2	Oxytocin	Resilient controls will self-administer 24 IUs of OT nasal spray at 10:30 a.m.on Day 1 of study procedures, approximately 45-minutes prior the scanning sessions. This dose and timing of administration were selected based on similar fMRI studies (Domes, et al., 2007; Domes, et al., 2010; Kirsch, et al., 2005).
PTSD Oxytocin Day 1, Placebo Day 2	Oxytocin	Participants with PTSD will self-administer 24 IUs of OT nasal spray at 10:30 a.m. on Day 1 of study procedures, approximately 45-minutes prior the scanning sessions. This dose and timing of administration were selected based on similar fMRI studies (Domes, et al., 2007; Domes, et al., 2010; Kirsch, et al., 2005).

Primary Outcome Measures

Name	Time	Method
Change in Amygdala Activation- Oxy Minus Placebo	Days 1 and 2	Bold signal response to facial recognition task was contrasted between oxytocin and saline administrations. Participants with PTSD and Resilient Controls each underwent 2 sets of scanning procedures, one with placebo and one with Oxytocin. Participants were randomly assigned to received Oxytocin on Day 1 or Day 2, and placebo on the opposite day, to mitigate crossover effects. Outcome measure is change in bold signal response between the two days; bold signal response on placebo was subtracted from bold signal response on Oxytocin to obtain change score.

Secondary Outcome Measures