Mental Imagery in Chronic Pain

1. University of Edinburgh Lothian Chronic Pain Service Mental Imagery in Chronic Pain David Gillanders University of Edinburgh / NHS Lothian Chronic Pain Service

2. What I’m going to tell you • A substantial proportion of chronic pain patients experience mental images of their pain • These images are associated with higher anxiety, depression, catastrophising, pain related worry

3. What we’ve done so far • The beginning: clinical work • Using Imagery for relaxation / manipulation • 3 studies: Louise Potter (2007) Tom Gosden (2008) Jennifer Lonsdale (2010)

4. Study 1 – Louise Potter’s Thesis • Postal Questionnaire study • 350 people who had attended pain clinic • 83 responses received (23%)

5. Measures • Pain • Disability • Catastrophising • Anxiety • Acceptance

6. Chronic Pain Imagery • “Some people report having mental images and/or pictures of their pain, do you have these?” • 24% YES (n = 19) • We then looked at differences between those reporting imagery and those not on the other measures.

7. Results Pain Non significant differences between imagers and non imagers: t = 1.97 (df = 1, 81) p = 0.053, d = 0.4 (though close!) Disability No significant difference: t = 0.8 (df = 1, 81) p = 0.42, d = 0.18 Due to the effect of pain we controlled for pain in all other analyses. Statistics are F statistics, p values and effect sizes of adjusted R2

8. Results • Anxiety Imagery group significantly more anxious than non imagery group F = 12.73 , (df 1, 80) p = 0.002 Effect size: adjusted R2 = 0.23 (23% of variance in HADS attributable to imagery, even after controlling for pain)

9. Results • Depression: Imagery group significantly more depressed F = 6.12, (df = 1, 80) p = 0.016 Effect size: adjusted R2= 0.12 (12% of variance in HADS D is attributable to imagery after controlling for pain)

10. Results • Catastrophising: Imagery group higher level of catastrophising thoughts F = 4.45, (df 1, 80) p = 0.038 Effect size: Adjusted R2= 0.21 (21% of variance in catastrophising attributable to imagery after pain)

11. Results • No other significant differences between groups • Acceptance (general or pain specific) • Other cognitive variables: resourcefulness, • coping thoughts, helplessness • Pain related anxiety though pain related worry is close: F = 3.73, (df = 1, 80), p = .057, adjusted R2 = .20

12. Conclusions • Some people recognise pain images and can report on these • Reporting these is associated with higher anxiety, depression and catastrophising, but not greater pain, disability or other psychological factors

13. Find out more about the characteristics of mental images Vividness Frequency Distress Interference Controllability Qualitative analysis of themes in mental image descriptions Study 2 – Tom Gosden’s Thesis

14. Methodology • Imagery Questionnaire • “We are particularly interested in finding out if you have a picture or a mental image of what your pain is like. A mental image is like having a picture in your head which may include things you can imagine seeing, hearing or feeling. Do you ever have a mental image like this of your pain?” • Qualitative Image description • Likert Type Scales • Vividness • Frequency • Distress • Interference • Controllability

15. Results • Participants • New patients seen at WGH in 12 months • Postal questionnaire (n=491) • 105 returns (22%) • 39% report having a mental image of pain

16. Results – Imagery Characteristics • Vividness:

17. Results – Imagery Characteristics • Frequency

18. Results – Imagery Characteristics * significant at the 0.05 level (two-tailed) ** significant at the 0.001 level (two-tailed)

19. Results – H1 Imagery & Pain • Imagery is associated with higher pain: t = 2.453 (df = 1,102), p = 0.016, d = 0.49

20. Results – H1 Imagery & Anxiety • Imagery is not associated with higher anxiety: t = 1.432 (df = 1, 91), p = 0.156, d = 0.30]

21. Results – H2 Imagery & Depression • Imagery is associated with higher depression: t = 2.042 (df = 1, 91), p = 0.044, d = 0.43

22. Thematic Analysis of Qualitative Descriptions • n=40

23. Theme 1. Representations of sensory qualities of pain Sub-theme: Pressure or weight “I have a mental image of a large hand inside the base of my spine squeezing as hard as it can, relentlessly…” (Participant 97)

24. Sub-theme:. Sharpness “If the pain is very sharp I imagine it as knitting needles being launched down various routes both in my back and legs” (Participant 104)

25. Sub-theme: Burning Heat “Fire going up and down my left side as if someone has a lighted torch trying to set my left side on fire” (Participant 27)

26. Sub-theme: Electricity “I have an image of an electric short circuit running down my legs!!” (Participant 93)

27. Theme 2. Anatomical Representations of Damage • “Bones grinding together” (Participant 32) • “The discs in my spine crumbling or grinding together causing my body to grind to a halt” (Participant 111)

28. Theme 3. A Ball of Pain • “My image looks like a large ball about the size of a tennis ball and it looks spongy and horrible” (Participant 14)

29. Theme 4. Victim of Attack • “Like my body is being attacked (where problems are) by someone with a voodoo doll or a little army inside me making sure I am in agony!” (Participant 6)

30. Study 3: Jennifer Lonsdale • Experimental study – within groups • Ratings of pain intensity and emotion state at baseline, then after verbal processing of pain and image processing of pain

31. Conditions • Imagery Condition – participants ‘contacted’ their usual pain image in some detail and described it • Verbal Condition – participants read and chose words from a list that best described their pain (based on the McGill Pain Questionnaire) they then constructed sentences to describe their pain using these words

32. Results – Impact on emotion Fear = no change Anger, Sadness, Happiness & Disgust: both verbal and imaginal conditions significantly different from baseline (t = .91 – 3.37 (df = 1, 35), p = .04 - .01) No significant differences between verbal and imaginal conditions for any emotion

33. Results – Impact on Pain No change from baseline to verbal (t = .54, (df 1,35) p = .6, ns) Pain significantly increased during imaginal condition (t= 2.56, (df 1,35),p = .02) Imagery processing of pain leads to enhancement of the sensory experience of pain significantly more than verbal processing of pain (t = 2.38, (df 1, 35), p = .02)

34. Next Steps • Grounded Theory Qualitative Study • Single Case Experimental Design

35. Conclusions • The fact we have replicated some of the findings of the earlier study is promising • Our understanding of this phenomenon is growing • Pain related images appear to be ways of making sense of abnormal sensory data

36. Conclusions • Images are a form of thought • We have a long history of measuring verbal thoughts and relatively little regarding non-verbal thoughts • We need studies to establish the validity, and reliability of ways of measuring imagery

37. Conclusions • Some images have themes of attack and / or future catastrophe • It is likely (though not yet established) that these kinds of thoughts will play a role in cueing avoidance behaviours • Imagery based interventions may be a useful addition to current exposure and cognitive restructuring interventions

38. Thank you for listening… david.gillanders@ed.ac.uk Acknowledgements: NHS Tayside Chronic Pain Service NHS Lothian Chronic Pain Service NHS Highland Chronic Pain Service Louise Potter Tom Gosden Paul Morris Jennifer Lonsdale Jennifer Snell Natalie Rooney Emily Newman Rachel Atherton Dee McDonnel-Boudra Clare Phillips, UBC Emily Holmes, Oxford Ann Hackmann, Oxford