Predicting posttraumatic stress disorder symptoms and pain intensity following severe injury: the role of catastrophizing

Abstract

Background: A number of theories have proposed possible mechanisms that may explain the high rates of comorbidity between posttraumatic stress disorder (PTSD) and persistent pain; however, there has been limited research investigating these factors.

Objective: The present study sought to prospectively examine whether catastrophizing predicted the development of PTSD symptoms and persistent pain following physical injury.

Design: Participants (N=208) completed measures of PTSD symptomatology, pain intensity and catastrophizing during hospitalization following severe injury, and 3 and 12 months postinjury. Cross-lagged path analysis explored the longitudinal relationship between these variables.

Results: Acute catastrophizing significantly predicted PTSD symptoms but not pain intensity 3 months postinjury. In turn, 3-month catastrophizing predicted pain intensity, but not PTSD symptoms 12 months postinjury. Indirect relations were also found between acute catastrophizing and 12-month PTSD symptoms and pain intensity. Relations were mediated via 3-month PTSD symptoms and 3-month catastrophizing, respectively. Acute symptoms did not predict 3-month catastrophizing and catastrophizing did not fully account for the relationship between PTSD symptoms and pain intensity.

Conclusions: Findings partially support theories that propose a role for catastrophizing processes in understanding vulnerability to pain and posttrauma symptomatology and, thus, a possible mechanism for comorbidity between these conditions.

Keywords: Posttraumatic stress; catastrophizing; comorbidity; injury; pain; path analysis; prospective.

Fig. 1

Saturated model containing all possible pathways. T1=acute period (M=6.1 days postinjury, SD=6.23); T2=3 months postinjury; T3=12 months postinjury). Bold lines represent direct effects from time one to time three variables.

Fig. 2

Final model following backward elimination of non-significant pathways. N=208. The figure displays standardized path coefficients between measures of PTSD, catastrophizing and pain severity. T1=acute (M=6.1 days postinjury, SD=6.23); T2=3 months postinjury; T3=12 months postinjury. Bold line represents direct effects from T1 to T3 variables. All correlations (not shown) were significant (T1 PTSD severity–T1 catastrophizing, β=.28**; T1 PTSD severity–T1 pain severity, β=.24**; T1 catastrophizing–T1 pain severity, β=.27**; T2 PTSD severity–T2 catastrophizing, β=.28**; T2 PTSD severity–T2 pain severity, β=.18*; T2 catastrophizing–T2 pain severity, β=.22**; T3 PTSD severity–T3 pain severity, β=.17**). p<.05; **p<.01