This longitudinal study of hospitalized survivors of community violence examined key issues concerning the interrelationship between posttraumatic distress and physical functioning. To our knowledge, this study is the first to systematically estimate the reciprocal cross-lagged relationships between these constructs over time. This investigation differs from other similar research in focusing on posttraumatic distress and physical functioning in the relatively immediate aftermath of trauma exposure. Results suggest a complex pattern of reciprocal effects. First, these findings document that early posttraumatic distress has a negative influence on subsequent physical functioning. Specifically, individuals who experienced greater distress in the days immediately following physical injury were more likely to report poorer than expected physical functioning at 3 month follow-up. This finding held, even after accounting for objective and subjective measures of injury severity. However, posttraumatic distress experienced 3-months post-injury was a less important determinant of long term physical functioning. Although the negative effects of acute posttraumatic distress may persist over time due to the high degree of stability in physical functioning after three months, we did not find significant evidence that later psychological distress continues to directly degrade physical functioning between three and 12 months. Findings also demonstrate that poor physical functioning is associated with subsequent posttraumatic distress. Specifically, we found that physical impairment at 3-month follow-up was linked to higher than expected levels of psychological distress at 12-month follow-up.
Our findings are particularly notable inasmuch as psychological research has previously shown relationships between distress and physical functioning, but has not demonstrated a temporal order in the development of these two constructs. The present study found evidence that PTSD symptoms and physical functioning problems can each precede the development of (or inhibit recovery from) the other problem. Individuals with high acute PTSD symptoms subsequently developed worse physical functioning at 3-month follow-up, whereas those with physical functioning problems at 3-months went on to develop worse than expected PTSD symptoms at 12-months. In prior longitudinal analyses, Schnurr and colleagues (2006)
examined PTSD symptoms among Vietnam veterans and found that changes in PTSD symptoms were negatively associated with changes in physical-health related quality of life during the same time. Similarly, Blanchard and colleagues (1997)
showed that physical recovery between a traumatic event and 4 months later was associated with remission of PTSD 6-months after the event. These earlier studies did not establish, however, whether physical health problems preceded changes in mental health or visa versa. Therefore, the present research goes beyond the previous investigations by documenting a temporal pattern that is consistent with reciprocal causal effects.
Our research was not designed to address the specific mechanisms that might underlie the effect of physical health on the subsequent development of PTSD symptoms and vice versa, although there are several mechanisms that may be operating. For example, one possibility is that physiological symptoms become cues of the cognitive, psychological, or behavioral response to the index trauma, and lead to posttraumatic distress (Resnick, Acierno, & Kilpatrick, 1997
). Another possibility is that lingering inability to perform basic tasks may make survivors more mindful of their traumatic experience than they otherwise might be. Recollection of the traumatic event may then trigger hyperarousal, avoidance, and other symptoms of posttraumatic stress disorder (Wessa & Flor, 2007
). Alternatively, physical impairment may limit occupational or social functioning, thereby increasing a traumatized individual’s reliance on coworkers, family, and friends to accomplish basic tasks which might also exacerbate symptoms of distress (Stein et al., 1997
). Another conjecture is that that poor physical functioning might also interfere with seeking mental health care for psychiatric problems, thus resulting in greater psychiatric distress (Smith, Schnurr, & Rosenheck, 2005
; Savoka & Rosenheck, 2000
). Research on the mechanisms underlying the observed relationships is needed, and might be informed by the results of the current study inasmuch as mechanisms should account not only for the association of distress and physical functioning in individuals with chronic PTSD but also must explain how distress might influence health relatively soon after trauma exposure.
Inasmuch as these data suggest that initial posttraumatic distress was more important than subsequent distress in predicting changes in physical functioning following sudden physical injury, our findings have important clinical implications. Currently, with few exceptions (Zatzick, 2003
), evaluation and treatment is uncommon for individuals at risk for PTSD following hospitalization for traumatic injury. This pattern is particularly true of our own sample in which less than 50% of individuals with mental health needs received care in the year following their assault (Jaycox et al., 2004
). Early intervention in trauma centers has been recommended as a means of preventing the development of PTSD (Zatzick, Russo, Roy-Byrne, Jurkovich, & Katon, 2005
). The current findings suggest that these interventions may promote both physical and emotional recovery in at least two ways. First, early intervention may reduce the likelihood of acute distress, which is directly and strongly linked with later PTSD symptoms. Moreover, the benefits of psychological interventions on acute posttraumatic distress may directly improve short-term (e.g., 3-month) physical functioning. Given that acute distress independently predicts physical functioning, the possibility exists that early psychological interventions aimed at reducing acute distress may improve subsequent physical functioning. To the extent that acute psychological distress may hamper posttraumatic physical functioning as well as posttraumatic mental health, these findings underscore the potential value of developing and implementing interventions for acute psychological care within the general trauma setting (e.g., Zatzick et al., 2005
Data from the current study suggest both that research examining the effectiveness of psychological interventions following trauma should continue to include physical functioning outcomes, and that new interventions be designed to consider the potential effects on physical functioning.
There are several limitations of the current study that highlight the need for additional research. First, like virtually all research on the relationship of posttraumatic distress and functional status (e.g., Holbrook et al., 2001
; Jacobsen et al., 1998
; Kapfhammer et al., 2004; Schnurr et al., 2006
; Kimerling et al., 2000; Michaels et al., 1999
; Paylo & Beck, 2005
; Magruder et al., 2004
), we relied on self-reported functional status. Although this strategy has proven valuable for many purposes, future research is needed to corroborate self-reported functional status with objective measures of functional status or other measures of health status. Moreover, given that we have no measure of self-reported physical health immediately after the attack, these data do not permit examination of the potential impact of physical functioning immediately following physical injury on subsequent health and well-being. Of course, it is likely that these measures would be highly collinear with our existing measures of injury severity inasmuch as physical functioning for physically injured patients who are interviewed shortly after hospitalization is likely to be heavily determined by their injury. To the extent that this information would prove valuable, however, further research is indicated. In addition, our sample also consisted primarily of young, urban, male, and Hispanic victims of community violence. Although studies of this group of individuals fills an important gap in the literature (Cabassa, Zayas, & Hansen, 2006
), future research is needed to discern the extent to which these findings may be generalizable to survivors from other sociodemographic backgrounds as well as survivors of different types of trauma. Furthermore, inasmuch as we studied individuals who had required hospitalization for the treatment of injuries, the relevance of these findings to those who experience less severe physical injuries is unclear. In addition, we introduced a minor change to a well-validated instrument assessing health status and health-related functioning to adjust for pre-existing differences in physical health (Hays, Prince-Embury, & Chen, 1998
). To the extent that this alteration introduced bias, additional research using truly prospective design to assess health status pre-injury would prove useful.
Finally, although this study examined symptoms of PTSD, our findings do not imply that symptoms of PTSD are uniquely related to functional impairment independently of other mental health constructs such as general distress or depressive symptoms. Research indicates, in fact, that symptoms of PTSD and depression are highly correlated following traumatic injury (e.g., O'Donnell, Creamer, & Pattison, 2004
; Shalev et al., 1998
). Moreover, much research has focused on the relationship between impaired physical functioning and symptoms of depression (Hays, Marshall, Wang, & Sherbourne, 1994
; Kosloski, Stull, Kercher, & Van Dussen, 2005
; Wells et al., 1989
). Although research has documented an independent effect of PTSD symptoms on physical health, particularly cardiovascular outcomes, independent of depressive symptoms (Boscarino & Chang, 1999
; Kubzansky et al., 2007
), future research might investigate whether symptoms of PTSD influence physical functioning independently of depressive symptoms and visa versa.
In summary, this longitudinal study examined the relationship between posttraumatic distress and physical functioning over time. Results indicate that higher levels of posttraumatic distress immediately following a violent injury presage a poorer physical recovery from the injury. In addition, lower physical functioning after an injury is linked with greater than expected posttraumatic distress at 12-month follow-up. Given the prevalence of community violence in the United States, further research on this topic has significant clinical and public health relevance. Interventions aimed at improving health in one domain should be investigated as having the potential to promote health in the other.