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					   Pain Psychology
MSc Pain Module, PHOL G008

         Jan 2005

   Lecture by Bruce Lynn
                Defining Pain

“     An unpleasant sensory and
    emotional experience associated
    with actual or potential tissue
    damage, or described in terms of
    such damage.”

        International Association for the Study of Pain 1979
     Understanding Pain:
  Contributions of Psychology
1. Rigorous methodology. Pain scales;
   questionnaires; use of randomisation, controls
2. Analysis of the placebo response
3. Directing attention to the emotional and cognitive
   factors that influence pain, such as depression,
   anxiety, memories, attention
4. Analysis of pain behaviour, especially the extent
   to which pain behaviour is conditioned or
   reinforced by family, clinicians etc
5. Development of treatment strategies such as
   cognitive-behavioural treatment
Placebo response

Depends on many factors

First look at effect of making the outcome criteria
more stringent
Effect of outcome criterion on response to placebo
Double blind migraine study

                                40
 % Patients achieving outcome


                                35
                                30
                                25
                                20
                                15
                                10
                                5
                                0
                                     No or Mild Pain   No or Mild Pain   No pain at 2   No pain at 24
                                       at 2 hours       at 24 hours         hours          hours



From: MD Ferrari et al. Meta-analysis of rizatriptan efficacy in randomized
controlled clinical trials. Cephalalgia 2001 21: 129-136.
Also see http://www.jr2.ox.ac.uk/bandolier/booth/Migraine/Riza2acu.html
Effect of outcome criterion on response to placebo and to
active drug. Note relative effect of placebo falls from around
50% with easy criterion to about 25% with harder criterion.

                                  80
   % Patients achieving outcome



                                  70
                                  60
                                  50
                                                                                              Placebo
                                  40
                                                                                              Rizatriptan
                                  30
                                  20
                                  10
                                  0
                                       No or Mild   No or Mild   No pain at 2 No pain at 24
                                       Pain at 2    Pain at 24      hours        hours
                                         hours        hours


  From: MD Ferrari et al. Meta-analysis of rizatriptan efficacy in randomized
  controlled clinical trials. Cephalalgia 2001 21: 129-136.
  Also see http://www.jr2.ox.ac.uk/bandolier/booth/Migraine/Riza2acu.html
       Contrasting definitions!




Recent analysis included 114 trials in 40 clinical conditions.
Concluded: “Not much evidence there, then, that doing nothing
makes things happen. “

That old placebo feeling, Bandolier, issue 99, May 2002
http://www.jr2.ox.ac.uk/bandolier/band99/b99-3.html
A Hröbjartsson & PC Gøtzsche. Is the placebo powerless? An analysis of
clinical trials comparing placebo with no treatment. New England Journal of
Medicine 2001 344: 1594-1602.
BUT

Neither of these definitions covers the typical clinical
situation.

There the placebo is a procedure accompanied by
suggestions and expectations of effectiveness.
It is under these conditions that (very) approx one third of
subjects experience a useful analgesic response.

In contrast the data analysed by Hröbjartsson & Gøtzsche
(2001) was mostly from clinical trials where steps are
taken to minimise the suggestion accompanying use of
active treatment or placebo procedure
    Depression is common in chronic pain patients.
    Anything from 14-65%, way above control group
    levels.
    Degree of depression is also greater in patients
    who rate their pain higher.
    But note many depression measures (e.g. Beck Depression
    Inventory, BDI) use criteria that include sleep disturbance,
    fatigue, problems at work, decreased appetite. These
    changes also occur in chronic pain, so care needs to be
    taken in interpreting some correlations between pain and
    depression.


Fishbain, D. A., Cutler, R., Rosomoff, H. L., & Rosomoff, R. S. (1997). Chronic pain-
associated depression: antecedent or consequence of chronic pain? A review. Clin.J
Pain 13, 116-137.
                  Depression                           Pain

                                     OR

                   Pain                     Depression

       Major review found 15 studies supporting the second
            hypothesis but only 3 supporting the first.



Fishbain, D. A., Cutler, R., Rosomoff, H. L., & Rosomoff, R. S. (1997). Chronic pain-
associated depression: antecedent or consequence of chronic pain? A review. Clin.J
Pain 13, 116-137.
At least 50% pain relief with antidepressant compared with
placebo in diabetic neuropathy, NNT=3




                                              Bandolier, issue 65,
                                              July 1999
                                              http://www.jr2.ox.ac.uk/ba
                                              ndolier/band65/b65-2.html
        Brain amines – a possible
        common cause for pain and
        depression

5-HT (Serotonin) and Noradrenaline levels are reduced in
depressed patients.
Both these amines are important for descending pain inhibition.
There is some evidence of reduced levels in chronic pain.
Antidepressant drugs that increase brain amines can sometimes
produce analgesia in chronic pain.


For discussion of the evidence, see review: Fishbain, D. A., Cutler, R., Rosomoff, H. L.,
& Rosomoff, R. S. (1997). Chronic pain-associated depression: antecedent or
consequence of chronic pain? A review. Clin.J Pain 13, 116-137.
         Is pain a learned behaviour?
  William Fordyce. Operant conditioning model.
  Pain behaviour is rewarded by solicitous attention, not having
  to work, access to drugs
  To treat need to: ignore pain behaviour, reward non-pain
  behaviour (e.g. physical activity)
  Also introduced regimen where analgesic drugs were reduced
  without patient knowing when (all drugs in syrup to conceal
  dose)
  Dose it work? Look at recent fibromyalgia study as an
  example.


Fordyce WE. Behavioral methods in chronic pain and illness. St. Louis: Mosby; 1976.
61 Fibromyalgia patients, all female.
Mean age 47, range 16-64
Duration pain, mean 16 years, range 0.6-36
In-patient programme, German clinic, Groups of 5-7, Daily sessions,
5 weeks
Operant group. Staged medication reduction; increased activity;
“reduction of interference of the pain in the family, at work, in leisure
time, and in social activities; reduction of pain behaviors in dealing
with the medical system; and training in assertive pain incompatible
behavior.” Significant others/family were involved where possible.
Comparator group received “standard” care comprising
physiotherapy (“included 7 different types of mainly passive physical
therapy exercises (e.g., muscle relaxation with thermotherapy, mud
bath, concentrated relaxation and light movement therapy in warm
water)”)
Both groups received 4 hours education plus 71 hours treatment
From: Operant behavioral treatment of fibromyalgia: A controlled study
K Thieme, E Gromnica-Ihle, H Flor, Arthritis & Rheumatism (2003) 49, 314-320
 Reduced pain score in fibromyalgia patients following in-
 patient operant behavioural programme. N=40, operant group;
 n=21, physiotherapy group. Note maintained improvement in
 the operant group - this was statistically significant.
                                      6
           MPI Pain Intensity Score



                                      5

                                      4
                                                                             Operant
                                      3
                                                                             Physio
                                      2

                                      1

                                      0
                                          Pre   Immed   6 month   15 month
                                                 Post


From: Operant behavioral treatment of fibromyalgia: A controlled study
K Thieme, E Gromnica-Ihle, H Flor, Arthritis & Rheumatism (2003) 49, 314-320
 Increased sleep in fibromyalgia patients following in-patient
 operant behavioural programme. N=40, operant group; n=21,
 physiotherapy group. Note again maintained improvement in
 the operant group that was statistically significant.

                                 8
                                 7
         Sleep duration, hours




                                 6
                                 5
                                                                        Operant
                                 4
                                                                        Physio
                                 3
                                 2
                                 1
                                 0
                                     Pre   Immed   6 month   15 month
                                            Post

From: Operant behavioral treatment of fibromyalgia: A controlled study
K Thieme, E Gromnica-Ihle, H Flor, Arthritis & Rheumatism (2003) 49, 314-320
 No change in total activity in fibromyalgia patients following
 in-patient operant behavioural programme. N=40, operant
 group; n=21, physiotherapy group. This contrasts with the
 improvements seen in pain score and sleeping.
                                    3.5
         MPI Total Activity Score




                                     3
                                    2.5
                                     2                                       Operant
                                    1.5                                      Physio

                                     1
                                    0.5
                                     0
                                          Pre   Immed   6 month   15 month
                                                 Post

From: Operant behavioral treatment of fibromyalgia: A controlled study
K Thieme, E Gromnica-Ihle, H Flor, Arthritis & Rheumatism (2003) 49, 314-320
Summary
Psychological approach has contributed greatly to
understanding pain problems, including:
• Placebo response and factors influencing it.
• The affective consequences of pain, such as depression,
and the importance of treating these.
• The cognitive issues involved in pain, for example the
role of unintended “conditioning” in determining pain
behaviour.
Finally, note that the distinction between “physiological”
and “psychological” aspects of pain is artificial, although
often useful. The clearest accounts involve a combined
biological-behavioural approach as exemplified by the
original gate control theory.

				
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