Universiteit Leiden

nl en

Research project

Placebo research: Training of the immune and endocrine system

The major aim is to unravel the central mechanisms of how peoples’ expectancies affect physical symptoms, immune and endocrine responses, and related health outcomes, through the use of pioneering multidisciplinary methods in experimental studies in healthy and clinical populations.

Contact
Andrea Evers
Funding
ERC Consolidator Grant
 
Dutch Arthritis Foundation Dutch Arthritis Foundation

Expectancies about health and disease, including chronic inflammatory itch and pain conditions, are known to induce immune and endocrine responses and directly affect health and treatment outcomes, with explained variance between 25-50%. However, there is an urge to understand the mechanistic underpinnings how these expectancies affect immune and endocrine responses and how this knowledge can be used for therapeutic interventions.

By means of a unique, ground-breaking dual-system approach of expectancy learning, this project will test for the first time whether combined automatic and conscious processes of expectancy learning (e.g., using both conditioning of previous treatment experiences and suggestions that a treatment is effective, together with personalized cues and exposure to relevant stressors) affect most profoundly immune and endocrine responses, in turn affecting health and disease outcomes. This interdisciplinary, cross-boundary project will progress key theoretical knowledge of the central expectancy mechanisms for immune and endocrine responses. Findings are of crucial importance for various health problems and treatments, opening new horizons for innovative health prevention strategies and therapeutic interventions for a broad range of inflammatory conditions and physical symptoms.


This ERC Consolidator Grant project is divided into five PhD projects: 

1. Expectancy mechanisms applied to the endocrine system: cortisol

Cortisol is a key stress-regulatory parameter, which is both influenced by and can influence the response to psychological treatment (e.g., pre-cortisol treatment in exposure therapy). This project examines whether it is possible to influence endogenous cortisol levels by means of expectancy mechanisms of conditioning and suggestions in healthy people and whether these expectancy mechanisms affect the psychophysiological response to stress. Results will have important implications for conditions in which patients have to receive long-term cortisol treatment, with accompanying adverse (side) effects.

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


2. Expectancy mechanisms applied to the endocrine system: endocrine hormones

Endocrine hormones such as oxytocin and testosterone have psychological and social effects in both animals and humans; for instance, oxytocin administration has anti-anxiolytic effects and leads to more prosocial behaviour. This project examines whether it is possible to influence endogenous hormone levels by means of expectancy mechanisms of conditioning and suggestions in healthy people and whether these expectancy mechanisms affect the psychophysiological response to relevant psychosocial stimuli. Results will have implications for the potential use of these mechanisms to stimulate prosocial and decrease antisocial behaviors.

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


3. Expectancy mechanisms applied to the immune system: allergies

Allergic responses 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 people and whether these expectancy mechanisms affect the anti-inflammatory response to physical stress. Results will have important implications for the treatment of allergic patients.

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


4. The effects of training applying expectancy mechanisms on inflammatory and stress responses

Preliminary research has shown that anti-inflammatory properties can be trained by means of an extensive training where psychological factors and exercise are combined; however, it is currently unclear whether psychological training combining expectancy mechanisms can have such effects on its own. This project examines whether it is possible to strengthen the stress and inflammatory response in healthy individuals by means of a psychological training combining expectancy mechanisms. By establishing the ability to strengthen the stress and immune response by means of psychological training, new therapeutic strategies can be developed and implemented for those with weak immune system responses.

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


5. The effects of conditioned pharmacotherapy 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. This project examines whether it is possible to improve the outcome (e.g., level of inflammation, side effects) 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. Pharmacotherapeutic treatment for patients with chronic inflammatory conditions could be optimized.

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

 

And a sixth PhD project is funded by the Dutch Arthritis Foundation (Reumafonds):


6. Placebo research: Training of the immune and endocrine system, chronic diseases

This research focuses on reducing methotrexate related side effects in the treatment for Juvenile Idiopathic Arthritis (JIA) by pharmacotherapeutic conditioning. In pharmacotherapeutic conditioning, placebo mechanisms like expectancy learning and associative learning (conditioning) can be employed in combination with pharmacological treatment to maximize treatment effects and control for side effects. Children diagnosed with arthritis report high intolerance rates to methotrexate and new approaches to reduce these side effects are urged. This study specifically aims to reduce these side effects by administrating MTX through a variable reinforcement schedule. (PI: prof. dr. Andrea W. M. Evers).

Supervisors Leiden University: Prof. dr. Andrea Evers, & Dr. Judy Veldhuijzen
And Prof. dr. Nico Wulffraat (UMCU)


PhD student: Rosanne Smits

This video can not be shown because you did not accept cookies.

You can leave our website to view this video.


This research program is part of the Research Group Psychoneurobiology of Health and Disease (www.andreaevers.nl) and is conducted in collaboration with the Leiden University Medical Center among other centers. 

Connection with other research

This website uses cookies. More information