A Randomized Clinical Trial of Mifepristone in PTSD

Posttraumatic stress disorder (PTSD) is a common and disabling psychiatric disorder. Left
untreated or under-treated, it can become a chronic condition associated with significant
distress, depression, aggression, family disruption, and substance abuse. There is also
accumulating evidence that combat-related PTSD is associated with an increased risk of
morbidity and mortality. For the welfare of returning veterans with PTSD and their families,
it is critical that this disorder is promptly identified and effectively treated.
Considerable advances that have been made in the assessment and treatment of PTSD in recent
years; however, psychopharmacological treatments have been shown to be largely ineffective
for veterans with PTSD.

To address this gap, this proposal seeks to test an innovative treatment approach in PTSD -
pharmacological manipulation of the body's major stress system (the
hypothalamic-pituitary-adrenal (HPA) axis) with mifepristone. At high doses mifepristone is
a glucocorticoid receptor (GR) antagonist with peripheral and central nervous system
effects, making it a compound of interest in the treatment of stress related disorders.
There is abundant evidence of enhanced GR sensitivity in veterans with PTSD which is thought
to underlie some of the symptoms of PTSD and associated disturbances in mood and cognition.
Thus, blockade of the GR receptor with mifepristone may target unique aspects of PTSD and
lead to clinically meaningful improvement in symptoms and cognition. There is preliminary
evidence that short-term mifepristone treatment has sustained beneficial effects on mood,
cognition and sleep disturbance in some neuropsychiatric conditions (major depression,
bipolar disorder, primary insomnia). That there can be sustained clinical and
neuropsychological effects of mifepristone and normalization of basal HPA axis activity
after drug discontinuation in these disorders, has led to the view that mifepristone's
actions include recalibration of a dysregulated HPA axis. Accordingly, we propose to study
the effects of mifepristone in veterans with chronic PTSD to determine if it is efficacious
in improving PTSD symptoms and associated clinical outcomes. To better understand the
mechanism of action of mifepristone we propose to assess the effects of mifepristone on HPA
axis activity and their relationship to treatment outcome and clinical response.

To achieve these objectives, we propose to conduct a Phase IIa, multi-site, double-blind,
placebo controlled trial of mifepristone in veteran outpatients with military-related PTSD
through the VA's Cooperative Clinical Trial Award program. We propose to enroll 136
unmedicated male veterans with military related PTSD at four VA sites (Albuquerque, NM,
Bronx, NY, Durham, NC, and San Diego, CA). Eligible veterans will be randomly assigned in
parallel groups to treatment with 600 mg/day mifepristone or placebo for one week and
followed for up to three months. Using statistical selection theory, we propose to determine
whether 600 mg of mifepristone yields a sufficiently high proportion of clinical responders
after one month to warrant more extensive and definitive research as part of a Phase III
trial. Secondarily, we seek to determine the effect of the dose of mifepristone compared to
placebo on the trajectory of CAPS scores and the time to addition of rescue medication, as
well as compare rates of adverse events and serious adverse events across the three groups.
We will also describe the effects of mifepristone on several other clinical parameters
including PTSD symptomology, depression severity, sleep quality, and functional impairment.
Several measures of neuroendocrine functioning will also be obtained to explore the
relationship of plasma cortisol and ACTH levels to clinical response and the time to
addition of rescue medications.