Effects of Paxil CR on Neural Circuits in Posttraumatic Stress Disorder (PTSD)
Status:
Completed
Trial end date:
2007-09-01
Target enrollment:
Participant gender:
Summary
Posttraumatic stress disorder (PTSD) is a major public health problem in this country. It is
estimated that at least one out of every seven women in our society have been the victim of
childhood sexual abuse at least once before their 18th birthday. Previous studies have shown
that stress is associated with damage to neurons of the hippocampus, a brain area involved in
learning and memory. Also, imaging studies of brain function are consistent with dysfunction
of the medial prefrontal cortex during presentation of traumatic cues. We have previously
shown that serotonin reuptake inhibitor medications (paroxetine; Paxil) can change memory
function and hippocampal structure in PTSD. We now propose to perform a placebo controlled
study with Paxil CR (paroxetine hydrochloride controlled-release tablets), which is thought
as paroxetine with less side-effects. The main purpose of this study is to determine the
effects of Paxil CR on memory deficits measured with neuropsychological testing, hippocampal
volume measured with a magnetic resonance imaging (MRI), medial prefrontal lobe cortical
function estimated with PET, and cortisol response (reflecting the intensity of stress) in
men and women with PTSD. We plan to recruit 40 subjects. After completing physical
examination and evaluating neuropsychiatric history, patients will undergo an initial group
of tests which includes memory testing, MRI and PET brain scan, and measurement of cortisol
in their saliva. Afterwards, half will receive Paxil CR 12.5 to 62.5 mg and half will receive
a placebo (sugar pill) in the beginning of the first 12 weeks as "Double Blind Phase". After
12 weeks, they will be administered memory tests, PET and MRI scan for the post-treatment
phase. After this period, Paxil CR will be offered to the placebo group and followed for an
additional 12 weeks. They will have final memory tests, and a MRI scan. We hypothesize that
Paxil CR exerts its efficacy by acting on abnormal neural circuits, including hippocampus and
prefrontal cortex, in PTSD.