THE IMPACT OF DISSOCIATION ON PTSD TREATMENT WITH COGNITIVE PROCESSING THERAPY

Background This secondary analysis of data from a randomized controlled trial of cognitive processing therapy ( CPT ) and its constituent components investigated whether dissociation decreased over the course of treatment primarily targeting symptoms of posttraumatic stress disorder ( PTSD ) and explored whether levels of dissociation predicted treatment outcome differentially by treatment condition . Methods An intention to treat sample of 150 women were randomized to CPT , cognitive therapy only ( CPT ‐ C ) or written trauma accounts only ( WA ). Dissociation was measured by the dissociation subscale of the T raumatic S tress I nventory and the M ultiscale D issociation I nventory . Results Multilevel regression analyses revealed significant decreases in dissociation that did not vary as a function of treatment condition. Growth curve modeling revealed significant treatment condition by dissociation interactions such that the impact of pretreatment levels of dissociation impacted the treatment conditions differently . Conclusions Women who endorsed low pretreatment levels of dissociation responded most efficiently to CPT ‐ C , whereas women with the highest levels of dissociation, in particular high levels of depersonalization, responded better to CPT .