Investigators also found that participants randomly assigned to receive WET were significantly less likely to drop out of treatment than those receiving PE.
Written exposure therapy involves writing about thoughts and feelings during a specific traumatic event during five supervised, 30-minute sessions and discussing the writing process with the therapist supervising the sessions.
In the latter sessions, the participant talks about how the event affected them.
“Clinicians should consider using WET in their practices as some clients would prefer a shorter treatment approach, and it may be the only option for some clients – for instance, those who have limited time for therapy and may not be able to do a longer treatment,” study investigator Denise Sloan, PhD, said in an interview.
She also noted that WET is covered by insurance and that “most providers I know indicate that they list it as CBT [cognitive-behavioral therapy] code to insurance companies.”
Sloan is senior clinician investigator of the National Center for PTSD at VA Boston Healthcare System and professor of psychiatry at Boston University.
The findings were published online in JAMA Psychiatry.
High attrition rates
The disadvantage to the three major types of therapy used most often to treat PTSD in veterans – eye movement desensitization and reprocessing, cognitive processing therapy (CPT), and PE – are the dropout rates, that range from 18% to as high as 50%.
Prior studies have shown that WET is briefer and just as effective as CPT, but investigators noted that it had never been tested against PE in a randomized clinical trial.
To find out how the two types of therapy compare, Dr. Sloan and associates randomized 178 veterans with PTSD from three VA centers – Boston; Charleston, S.C.; and Madison, Wisc. – to receive either WET or PE.
PE consisted of 8-15 90-minute therapy sessions during which participants imagine the most distressing aspect of their traumatic memory, and between sessions, they confront the people, places, or situations they have been avoiding because of the trauma.
The investigators used the Structured Clinical Interview for DSM-5 at baseline to screen participants at high risk for suicide, comorbid substance use disorder, and unstable bipolar disorder, who were excluded from the study.
At baseline, 10, 20, and 30 weeks after the first treatment session, the investigators measured the severity of each patient’s PTSD symptoms with the Clinician-Administered PTSD Scale for DSM-5, which has a range of 0 (no PTSD symptoms) to 80 (most severe PTSD symptoms).
Of the 178 veterans, 134 were men, and their mean age was 45 years. The majority (63%) was White, while 21% were Black.
The researchers found that study participants were not significantly more likely to meet PTSD diagnostic criteria in the WET or PE conditions at any assessment.
WET briefer, better retention
Investigators noted the largest difference in PTSD scores in favor of WET at the 10-month assessment: The mean score for those receiving WET was 27.7, and the mean score for those receiving PE was 30.1 (odds ratio, 0.72; 95% CI, 0.35-1.46).
Among those who finished treatment, the mean number of treatment sessions was 12.5 for PE and 6 for WET.
Participants assigned to receive PE were significantly more likely to drop out of the study prematurely; 32 (35.6%) dropped out, compared with 11 (12.5%) participants assigned to WET.
Notably, of the 32 participants who dropped out of PE, 30 did so by session 7, so the increased dropout in PE was not related to the greater number of sessions, the investigators noted.
They added that findings could have been limited by stressors related to the global COVID-19 pandemic, which was taking place during the treatment, and the fact that all of the participants were veterans, which could limit the generalizability of the findings.
In an editorial, Charles Taylor, PhD, and Murray Stein, MD, MPH, both from the department of psychiatry at the University of California, San Diego, wrote that “WET achieved comparable reductions in PTSD symptoms through fewer sessions, shorter duration sessions, less therapist involvement, and no explicit prescription of homework.
“These findings should galvanize the psychotherapy field to design parsimonious treatments from the start, systematically testing the effects of different dose parameters,” they concluded.
The study was supported by the VA. Dr. Sloan reported receiving royalty payments for the published Written Exposure Therapy manual from the American Psychological Association outside the submitted work.
A version of this article appeared on Medscape.com.