The flexible application of a manualized treatment for PTSD symptoms and functional impairment related to the 9/11 World Trade Center attack

The purpose of this treatment effectiveness study was to evaluate the flexible application of a manualized cognitive behavioral treatment (CBT) for PTSD and related symptoms in survivors of the 9/11 terrorist attack on the World Trade Center. Treatment delivery ranged from 12 to 25 sessions; therapist experience ranged from no prior training to extensive training in CBT; and training and supervision of clinicians in the treatment manual was considerably less than that required in a randomized clinical trial (RCT). Paired t-tests demonstrated significant pre–post reductions in symptoms of PTSD and depression for the flexible application of the treatment. A benchmarking analysis revealed that the moderate-to-large effect sizes found for these variables were similar to those obtained in an RCT of the same treatment. Furthermore, effect sizes on measures of outcomes particularly relevant to this population of mass violence survivors such as functional impairment, use of alcohol and drugs to cope, and use of social support to cope, were also medium to large.