The utility of the A1 and A2 criteria in the diagnosis of PTSD

Abstract

In the field of posttraumatic stress disorder (PTSD), the revisions to the DSM-IV definition of a potentially traumatic event are contentious. Proponents praise the subjective emphasis, while others contend that the changes to the criterion broadened the conceptualization of PTSD. This study examined the predictive utility of Criterion A events, examining the stressor (A1) and subjective emotional response (A2) components of the definition of a traumatic event. Rates of Criterion A events and PTSD were calculated for three diverse samples, and predictive power, sensitivity, specificity, and ROC curves were computed to determine the predictive utility of Criterion A requirements for PTSD symptom, duration, and functional impairment diagnostic criteria. Across all samples, the current Criterion A requirements did not predict much better than chance. Specifically, A2 reports added little to the predictive ability of an A1 stressor, though the absence of A2 predicted the absence of PTSD-related symptoms, their duration, and impairment. Notably, the combination of three A1 and A2 criteria showed the best prediction. Confronted events also showed less predictive ability than experienced events, with more variable performance across samples. These results raise fundamental questions about the threshold or "gate" that Criterion A ought to play in our current nosology.

Figure 1

Receiver Operating Curves: (Figure 1a) showing predictive power of Criterion A (1, 2, 3, and 4 criteria) for other PTSD diagnostic criteria (symptoms, duration, and impairment only) across three samples: female undergraduate (Sample 1), mixed undergraduate (Sample 2) and community trauma-exposed (Sample 3); and (Figure 1b) across experienced and confronted events separately for each sample. Each curve represents a sample or subsample. Each data point on a curve represents a particular cutoff of symptoms, reading left to right moving from the lower left-hand corner "0" to the upper right-hand corner "1", with the first data point representing any one of four possible Criterion A endorsements, the second, any two of four possible Criterion A endorsements, the third, any three of four possible Criterion A endorsements, and the fourth, all four of the possible Criterion A endorsements. Greater bowing of the curve represents better prediction.

Figure 1

Receiver Operating Curves: (Figure 1a) showing predictive power of Criterion A (1, 2, 3, and 4 criteria) for other PTSD diagnostic criteria (symptoms, duration, and impairment only) across three samples: female undergraduate (Sample 1), mixed undergraduate (Sample 2) and community trauma-exposed (Sample 3); and (Figure 1b) across experienced and confronted events separately for each sample. Each curve represents a sample or subsample. Each data point on a curve represents a particular cutoff of symptoms, reading left to right moving from the lower left-hand corner "0" to the upper right-hand corner "1", with the first data point representing any one of four possible Criterion A endorsements, the second, any two of four possible Criterion A endorsements, the third, any three of four possible Criterion A endorsements, and the fourth, all four of the possible Criterion A endorsements. Greater bowing of the curve represents better prediction.