Why is it that some people develop chronic pain after recovering from an injury, while others don’t? Suppose you are one of the many people who had an injury. Let us further assume that you were the one in five who develops chronic pain after injury. You might misinterpret the pain (e.g., you thought that the pain you were feeling was an indication that something worse may happen), you become fearful of situations associated with pain (e.g. you are afraid to make movements) and because you are afraid, you avoid these situations (e.g. not going to work anymore because you are scared the pain will get worse). According to the fear avoidance model this pathway can lead to a chronic pain condition (Vlaeyen & Linton, 2000; 2012).
A lot of research has focused on pain-related fear, but far less is known about the potential detrimental effects of pain-related avoidance behaviour. Working as a PhD student in pain research, I examine the effects of avoidance behaviour on pain-related fear and threat beliefs. Recently a bidirectional relationship has been proposed, in whicht engaging in avoidance may not only be a response to fear, but also in itself may maintain and increase fear (Volders, Boddez, De Peuter, Meulders, & Vlaeyen, 2015). But almost no research has been dedicated to whether avoidance behaviour itself leads to pain-related fear. As a consequence, the relationships between avoidance behaviour, pain-related fear and, threat beliefs remain unclear.
In our recent study (van Vliet, Meulders, Vancleef, & Vlaeyen, 2018), we tested whether avoiding a painful stimulus leads to increases in pain-related fear and threat beliefs in a pain-free population. We invited 64 participants to the lab. One half of the participants were assigned to the avoidance group, the other half to the control group. Avoidance group participants were led to believe they could avoid full exposure to a painful heat stimulus by pressing the stop-button when instructed, while control group participants were exposed to the full painful heat stimulus at all times. In reality and unknown to the participants, the intensity and duration of the heat stimulus was independent of the avoidance response, and was identical in both groups. During the test, the avoidance response (that is, pressing the stop button) was no longer available for the participants in the avoidance group. For every participant we assessed self-reported ratings on (1) pain-related fear, (2) threat beliefs and, (3) pain.
So what did we find? Pain-related fear increased for avoidance group participants before they actually engaged in avoidance behaviour, and these elevated levels of pain-related fear were maintained after the avoidance behaviour was employed, despite equal intensities and duration of the heat stimulus. Furthermore, we found a decrease of threat beliefs in the control group, while the threat beliefs about the heat stimulus in the avoidance group remained the same. We also observed a reduction in perceived pain intensity that was achieved by engaging in avoidance behaviour, while the physical intensity of the heat stimulus did not change throughout the experiment.
What does this mean? The observed increase of pain-related fear as a result of avoidance behaviour is in line with previous research, which was mainly conducted in the field of anxiety disorders (Engelhard, van Uijen, van Seters, & Velu, 2015; Gangemi, Mancini, & van den Hout, 2012). For example, chronic pain patients might conclude that their own actions like avoiding certain movements prevent feared outcomes (e.g. having more pain), thereby leading them to draw invalid conclusions about the situation (behaviour as information). This tendency to infer danger on the basis of avoidance behaviour may start a vicious circle: avoidance behaviour increases fear and maintains threat beliefs in turn increasing avoidance behaviour, and so on.
To conclude, the results of this study suggest that avoidance behaviour in itself may play a role in increasing fear and maintaining threat beliefs. Allowing avoidance behaviours in clinical therapy may be detrimental for fear reduction and this should be taken into account when providing clinical recommendations.
For the full story, please check out the recently published article here: The Opportunity to Avoid Pain May Paradoxically Increase Fear
About Christine van Vliet
Christine van Vliet obtained her Master of Science degree in Psychology, Theory and Research at the university of Leuven, Belgium. She is currently a doctoral researcher in the Research Group on Health Psychology at the University of Leuven and Experimental Health Psychology at Maastricht University (the Netherlands) under the supervision of Johan Vlaeyen, Ann Meulders and Linda Vancleef. Her PhD research concerns the effects of pain-related avoidance behaviours on pain-related fear, threat beliefs and pain perception. These processes are investigated using experimental laboratory research with healthy participants.
References
Engelhard, I. M., van Uijen, S. L., van Seters, N., & Velu, N. (2015). The effects of satefy behaviour directed towards a safety cue on perceptions of threat. Behavior therapy, 46(5), 604-610.
Gangemi, A., Mancini, F., & van den Hout, M. (2012). Behavior as information: “If I avoid, then there must be a danger”. Journal of behavior therapy and experimental psychiatry, 43(4), 1032-1038.
van Vliet, C. M., Meulders, A., Vancleef, L. M., & Vlaeyen, J. W. (2018). The opportunity to avoid pain may paradoxically increase fear. The Journal of Pain. In press.
Vlaeyen, J. W. S., & Linton, S. J. (2000). Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain, 85, 317-332.
Vlaeyen, J. W. S., & Linton, S. J. (2012). Fear-avoidance model of chronic musculoskeletal pain: 12 years on. Pain, 153, 1144-1147.
Volders, S., Boddez, Y., De Peuter, S., Meulders, A., & Vlaeyen, J. W. S. (2015). Avoidance behavior in chronic pain research: A cold case revisited. Behaviour Research and Therapy, 64, 31–37. https://doi.org/10.1016/j.brat.2014.11.003