Universiteit Leiden

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Research project

Psychoneurobiology in itch and pain

The major aim is to unravel the psychoneurobiological factors, such as expectations, sensitization and attentional processes, that affect the experience of itch and pain in acute and chronic state.

Funding
NWO Vidi Grant
 
ERC Consolidator Grant
 
ZON-NW Doelmatigheid ZON-NW Doelmatigheid
 
Pfizer Pharmaceuticals Pfizer Pharmaceuticals

Although pain and itch are distinct somatosensory sensations, they share neurobiological pathways, can interact at the spinal cord level (e.g., pain can reduce itch by scratching), and activate corresponding brain areas. Psychoneurobiological processes, such as expectations, sensitization and  attentional processes, have frequently been shown to play an important role in acute and chronic pain and more recently also in itch.

Research into the psychoneurobiology of itch in comparison to pain is the focus of different projects (see also research program “Placebo research: Pain and itch” and “Psychophysiological factors in itch and pain”, “Placebo research: Training of the immune and endocrine system”, “Tailored cognitive-behavioral e-Health care for patients with chronic somatic conditions”):
 

1. Itch and pain: Common and distinct psychophysiological factors (finished PhD project)

In this project, different psychophysiological aspects, i.e., sensory, cognitive and affective factors, were investigated regarding both itch and pain. Studies investigating sensory aspects showed that patients with chronic itch and pain generally displayed a heightened sensitivity to itch and pain, generally and symptom-congruently (e.g., patients with chronic itch to itch). In addition, patients with chronic itch also showed an impaired central modulation of itch by conditioned itch modulation. With respect to affective-motivational factors, was shown that negative rather than positive emotions resulted in a heightened itch and pain sensitivity. As to cognitive aspects, it has been shown that inducing negative expectations led to increases in itch and pain, with stronger effects for itch.

These studies were conducted in the context of the PhD project of Antoinette van Laarhoven, with Prof. dr. Andrea Evers as the first promotor.
 

2. Induction of expectancy mechanisms underlying placebo and nocebo effects applied to physical sensations

Placebo and nocebo effects (expectation of symptom reduction and induction) for both pain and itch are induced and trained in healthy controls and patients, using validated and innovative procedures of classical conditioning and placebo-related outcome expectancies. This project examines the mechanisms underlying placebo and nocebo effects with regard to physical sensations, such as itch. Expectancy learning mechanisms of verbal suggestions and conditioning are investigated with regard to inducing and counteracting placebo and nocebo effects. Additionally, the role of cognitive schemas of placebo-related outcome expectancies, and individual differences in placebo responding are investigated.

Supervisors Leiden University: Prof.dr. Andrea Evers & Dr. Antoinette van Laarhoven.
PhD student: Danielle Bartels.

 

3. Training of expectancy mechanisms underlying placebo and nocebo effects applied to physical sensations

This project focuses on the comparative and additive effects of various expectancy trainings including imagery and verbal suggestions on physical sensations, such as pain, itch, and fatigue. The effects of expectations on both self-reported and psychophysiological outcomes are examined.

Finished PhD project
These studies were conducted in the context of the PhD project of Kaya Peerdeman, with Prof. dr. Andrea Evers as the first promotor, & Dr. Antoinette van Laarhoven as co-promotor.

4. Expectancy mechanisms applied to the immune system: allergies

Allergic responses, such as itch, have been shown to be susceptible to the effects of expectancy mechanisms. Less is known about the ability to lessen allergic symptoms by means of such learning processes. This project examines whether it is possible to influence endogenous immune levels by means of expectancy mechanisms of conditioning and suggestions in healthy subjects and whether these expectancy mechanisms affect the anti-inflammatory response and itch symptoms. Results will have important implications for the treatment of allergic patients with itch symptoms.

Supervisors Leiden University: Prof.dr. Andrea Evers, Dr. Henriët van Middendorp, & Dr. Judy Veldhuijzen.
PhD student: Stefanie Meeuwis.
 

5. The effects of conditioned pharamcotherapy for chronic inflammatory conditions

Although treatment for chronic inflammatory conditions such as rheumatoid arthritis (RA) has improved considerably, most pharmacotherapeutic strategies are accompanied by more or less severe side effects. These projects examine whether it is possible to improve the outcome (e.g., level of inflammation, side effects, symptoms of pain and itch) of pharmacotherapy in patients with chronic inflammatory conditions by means of expectancy mechanisms of variable treatment schedules (conditioning) and suggestions on the effectiveness of the treatment. In the long-term, this can result in optimalisation and possible reduction of pharmacotherapeutic treatment for patients with chronic inflammatory conditions.

Supervisors Leiden University: Prof.dr. Andrea Evers, Dr. Henriët van Middendorp, & Dr. Judy Veldhuijzen.


6. Tailored cognitive-behavioral e-Health care in patients with chronic pain

The objective of this project is to examine the (cost)effectiveness of tailored cognitive-behavioral therapy through e-Health for risk groups of patients with chronic pain of rheumatoid arthritis versus standard care, in collaboration with the Radboud university medical center.

Supervisors Leiden University: Prof.dr. Andrea Evers & Dr. Henriët van Middendorp.
PhD student: Maaike Ferwerda.


7. Tailored cognitive-behavioral E-health care in patients with itch

This project entails a randomized controlled trial to examine the effectiveness of tailored cognitive-behavioral treatment for patients with psoriasis suffering frequently from chronic itch, compared to patients receiving standard dermatological care (care as usual), in collaboration with the Radboud university medical center.

Finished PhD project
These studies were conducted in the context of the PhD project of Sylvia van Beugen, with Prof. dr. Andrea Evers as the first promotor, & Dr. Henriët van Middendorp as co-promotor.


8. Grip on Pain

This project is part of a national project (‘Grip op onbegrepen klachten’) that is conducted in collaboration with the University Medical Center Groningen and the Radboudumc. Grip on Pain aims to implement and evaluate an online chronic pain treatment within various health care centers.  

Researchers Leiden University: Prof.dr. Andrea Evers, Dr. Henriët van Middendorp & Dr. Roos van der Vaart.
 

This research program is part of the Research Group Psychoneurobiology of Health and Disease (www.andreaevers.nl)

Connection with other research