Investigators randomly assigned individuals with PTSD to receive either exposure therapy with aerobic exercise or exposure therapy with passive stretching for 9 weeks. At 6 months post intervention, participants in the aerobic exercise group showed greater reductions in PTSD severity, compared with those in the stretching group.
“There is a critical need to improve outcomes for treating people with PTSD, and this finding points to one potentially cheap and ready-to-use strategy that all clinicians could employ with most patients,” lead author Richard Bryant, MPsych, PhD, DSc, director of the Traumatic Stress Clinic and Scientia Professor of Psychology at the University of New South Wales, Sydney, told this news organization.
The study was published online in The Lancet Psychiatry.
Promoting BDNF
“Trauma-focused psychotherapy is the recommended treatment for PTSD, but up to half of patients do not respond to this treatment,” Dr. Bryant said.
“We know that brain-derived neurotrophic factors [BDNF] are critical for synaptic plasticity, which underpins the learning that occurs in therapy so that reminders of trauma are no longer fear-provoking,” he continued. “Preclinical animal and human research inform us that brief aerobic exercise can promote BDNF and new learning that inhibits fear responses.”
The researchers “hypothesized that brief exercise after exposure therapy to trauma memories – which is the key ingredient of trauma-focused psychotherapy – would lead to greater reductions in PTSD, relative to standard trauma-focused therapy,” he said.
To investigate the question, the researchers randomly assigned 130 adults with PTSD (mean age, 39 years; 61% female; 76% White) to receive nine 90-minute sessions of exposure therapy with either aerobic exercise or passive stretching (n = 65 in each group).
There were no differences at baseline in sociodemographic characteristics or psychopathology measures, although the mean age of the stretching group was slightly older than that of the aerobic group (40 years vs. 37 years, respectively), and there was a slightly higher proportion of women in the stretching group (68% vs. 54%).
Participants did not differ on weekly exercise either at baseline, immediately post treatment, or at 6-week follow-up.
PTSD severity (the primary outcome) was measured using the clinician-administered PTSD scale CAPS-2, with assessments conducted at baseline, 1 week post treatment, and 6 months post treatment.
The aerobic exercise regimen was tailored to each participant, based on an assessment of his/her aerobic target zone.
The exposure therapy sessions were identical for both groups. Following the exposure sessions, participants engaged in their respective exercises: Those in the passive stretching group engaged in 20 minutes of exercise, while those in the aerobic group participated in a total of 20 minutes of exercise, with 10 conducted at their personal aerobic target heart rate.
“This level of exercise was chosen because BDNF concentration in the serum is increased by two 3-minute bouts of aerobic exercise, and 10 minutes of aerobic exercise can facilitate extinction learning,” the authors explained.
The aerobic activity consisted of running on a stepper exercise platform while having cardiac activity recorded. A small portion (10%) of the therapy sessions were recorded and rated for treatment fidelity.
Change in PTSD was the primary outcome, with secondary outcomes consisting of changes in depression, anxiety, alcohol use disorder, and posttraumatic cognitions.