Does the modified Stroop effect exist in PTSD? Evidence from dissertation abstracts and the peer reviewed literature.

The modified Stroop effect (MSE), in which participants show delayed colour naming to trauma-specific words, is one of the most widely cited findings in the literature pertaining to cognitive bias in posttraumatic stress disorder (PTSD). The current study used a novel approach (Dissertation Abstract Review; DAR) to review the presence of the MSE in dissertation abstracts. A review of dissertations that used the modified Stroop task in a PTSD sample revealed that only 8% of the studies found delayed reaction times to trauma-specific words in participants with PTSD. The most common finding (75%) was for no PTSD-specific effects in colour naming trauma-relevant words. This ratio is significantly lower than ratios found in the peer reviewed literature, but even in the peer reviewed literature only 44% of controlled studies found the modified Stroop effect. These data suggest that a reevaluation of the MSE in PTSD is warranted.