Sunday, July 08, 2012

"Everything you wanted to know about phobias and were afraid to ask" - Gordon Asmundson on fear avoidance

Gordon Asmundson, with students at U of Regina
The second speaker PSD arranged for CPA Congress this spring (see this blogpost for our first, David "Believe in your Placebo"Seminowicz), was Gordon Asmundson, "Ph.D., R. D. Psych, FRSC.. Full Professor of Psychology at the University of Regina, Adjunct Professor of Psychiatry at the University of Saskatchewan, and the leader of a CIHR New Emerging Team focusing on mechanisms and treatment of PTSD", a very prolific researcher with 230 peer-reviewed journal articles (170 of which can be found listed on PubMed), over 50 book chapters, and 6 books. 

His talk was on the need to define important constructs in understanding chronic pain, study models, develop state of the art science, develop treatment options, and examine considerations for the future. The big take-home message: Fear Avoidance (FA) models help explain chronic pain experienced by some people.

The FA model can be generalized to children, attempts to explain how pain relates to anxiety and fear disorders. Pain involves cognitions and emotions as well as sensations. 
Fear differs from anxiety 
1. If a threat is present, fear can fuel escape, which is a defensive behaviour.  
2. Anxiety, however, has more to do with future avoidance, or preventive behaviour.  
3. Both involve threat, both are adaptive; both, however, can become maladaptive. 
Associations between fear/anxiety and pain have been recognized for centuries; it has been learned they have distinct yet overlapping neurobiology. Early key contributors were Fordyce (1976) (1), Letham 1983 (2),  and Philips(1987) (3) [from Asmundson et al, Fear and avoidance in dysfunctional chronic back pain patientsPain 69 (1997) 231–236].

Stimulus is influenced by threat value - e.g., proximity of spider, and threat value really influences the 
response, or salience (Arntz & Claassens 2004)(4). If a subject had been primed to expect "cold", they reported less damage/pain. A significant percentage of people place a high threat value on "pain". High "catastrophizers" overestimated how bad an activity would be (Crombez 2002)(5). All this can result in a downward spiral for these individuals in pain, similar to anxiety disorders. 

Pain experience can go one of two ways: toward confrontation and recovery, or toward avoidance and catastrophizing. (Vlaeyen and Linton 2000)(6). Seeing a headline like "World Death Rate Holding Steady At 100 Percent" (from the Onion, a satirical faux-news publication), will either induce a nod toward an obvious fact, or feed a tendency toward anxiety. Catastrophic headlines are ubiquitous.

Basics of fear and anxiety:
Avoidance feeds high reactivity, disturbs many brain loops. Those with high anxiety and sensitivity can become worried over normal, benign, harmless bodily sensations, such as their own heart beat. Testing individuals for anxiety involves asking for grade on statements, such as, "It's important for me not to appear nervous." A meta-analytic review involving 5,908 participants determined association between anxiety sensitivity and pain (Ocañez 2010)(7).  

The model continues to be tweaked:
Iterations continue (Leeuw 2007)(8). Threatening illness information feeds fear of pain, and avoidance. Some people are predisposed to perceive pain and pain-related arousal as threatening, which leads to escape behaviour. Numerous reviews of the fear avoidance model have appeared, most of which support it. One can use structural equation modeling to ask, Do the models fit the data? - to find out, one can test the pathways in the model (Asmundson and Taylor 1996)(9). Pain intensity and escape behaviour are closely related. A Martin 2010 (PTSD) model fits the data better (10); self-perpetuating cycle holds (Asmundson 2012)(11). 

"Everything you wanted to know about phobias and were afraid to ask"
It makes sense to treat fear and anxieties ahead rather than pain (in chronic pain patients). Establish treatment goals. Educate on the paradox of avoidance behaviours. Avoidance has short term benefits, but in the end is a roller coaster, and does nothing to enhance capacity. But how? Graded exposure. The fear network has to be activated, but just by a little bit. Think of teaching children to swim. Fear of spiders? Expose the patient to the curds, but not the spider. Use reassurance, education, and exercise introduced carefully. Treat the "fear" and the "fear amplifier - "interoceptive exposure". 
Graded in vivo exposure involves a set fear heirarchy, using a standardized set of images. People work through the images, with physiology monitored. The idea is to increase activity without increasing fear and anxiety. Fear declines as avoidance is overcome. When fear declines, so does pain! (Woods and Asmundson 2008)(12). Help patients with interoceptive exposure, to become more familiar with feeling the body changing. There is not a lot of evidence yet, but it appears to work, and is about to be studied more deeply (Watt 2006)(13). 

The model postulates appear to generalize to children, but different assessment tools are needed (Wicksell et al 2005, 08, 09)(14, 15, 16). For children the context is very important; and modelling of pain behaviours must be monitored, for example, modelling by parents. 

In summary:
Context has direct input into fear and anxiety. The model needs to be considered in its broader social context, and psychotherapy approaches such as attention modification, acceptance and mindfulness, etc., adopted.  

Published the same day as Asmundson's presentation: 

1. Fordyce, W.E., Behavioral Methods For Chronic Pain and Illness, Mosby, St. Louis, 1976
2. Letham, J., Slade, P.D., Troup, J.D.G. and Bentley, G., Outline of a fear-avoidance model of exaggerated pain perception - I, Behav. Res.Ther., 21 (1983) 401–408. (no abstract)
3. Philips, H., Avoidance behaviour and its role in sustaining chronic pain, Behav. Res. Ther., 25 (1987) 273–279. (no abstract)
4. Arntz AClaassens L.; The meaning of pain influences its experienced intensityPain. 2004 May;109(1-2):20-5
5. Crombez GEccleston CVan den Broeck AVan Houdenhove BGoubert L.; The effects of catastrophic thinking about pain on attentional interference by pain: no mediation of negative affectivity in healthy volunteers and in patients with low back painPain Res Manag. 2002 Spring;7(1):31-9.
6. Vlaeyen JWLinton SJFear-avoidance and its consequences in chronic musculoskeletal pain: a state of the artPain. 2000 Apr;85(3):317-32.
7. Ocañez KLMcHugh RKOtto MW.; A meta-analytic review of the association between anxiety sensitivity and painDepress Anxiety. 2010 Aug; 27(8):760-7
8. Leeuw MGoossens MELinton SJCrombez GBoersma KVlaeyen JWThe fear-avoidance model of musculoskeletal pain: current state of scientific evidenceJ Behav Med. 2007 Feb;30(1):77-94. Epub 2006 Dec 20.
9. Asmundson GJTaylor SRole of anxiety sensitivity in pain-related fear and avoidanceJ Behav Med. 1996 Dec;19(6):577-86.
10. Anke Ehlers, Oliver Suendermann, Inga Boellinghaus, Anna Vossbeck-Elsebusch, Matthias Gamer, Emma Briddon, Melanie Walwyn Martin, and Edward GlucksmanHeart rate responses to standardized trauma-related pictures in acute posttraumatic stress disorderInt J Psychophysiol. 2010 October; 78(1): 27–34. doi:  10.1016/j.ijpsycho.2010.04.009 (Full Access)
11.  Fetzner MGCollimore KCCarleton RNAsmundson GJ.  Clarifying the relationship between AS dimensions and PTSD symptom clusters: are negative and positive affectivity theoretically relevant constructsCogn Behav Ther. 2012 Mar;41(1):15-25. Epub 2011 Nov 1.
12. Woods MPAsmundson GJ;  Evaluating the efficacy of graded in vivo exposure for the treatment of fear in patients with chronic back pain: a randomized controlled clinical trial. Pain. 2008 Jun;136(3):271-80. Epub 2007 Aug 22.
13. Watt MCStewart SHLefaivre MJUman LS.;  A brief cognitive-behavioral approach to reducing anxiety sensitivity decreases pain-related anxietyCogn Behav Ther. 2006;35(4):248-56.
14. Wicksell RKKihlgren MMelin LEeg-Olofsson O.; Specific cognitive deficits are common in children with Duchenne muscular dystrophy. Dev Med Child Neurol. 2004 Mar;46(3):154-9.
15. Wicksell RKMelin LOlsson GL.; Exposure and acceptance in the rehabilitation of adolescents with idiopathic chronic pain - a pilot studyEur J Pain. 2007 Apr;11(3):267-74. Epub 2006 Apr 17. 

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