HaPpY · Comorbidity of cHronic Pain and mood disorders: breaking the vicious cYcle

Comorbidity of cHronic Pain and mood disorders: breaking the vicious cYcle

The increasing number of individuals with comorbidities poses an urgent need to improve the management of patients with multiple co-existing diseases. Among these comorbidities, chronic pain and mood disorders, two long-lasting disabling conditions that significantly reduce the quality of life, could be cited first. Chronic pain and neuropsychiatric disorders represent a major threat to Europe both socially and economically and this threat is set to increase with the ageing population. In the European Union, it is estimated that 27% of the population suffers from a mood disorder and 20% from chronic pain during lifespan and that these are the most important risk factors for suicide. Overwhelming evidence suggests that chronic pain and mood disorders do more than co-occur, they also promote the development of each other and have a negative impact on the successful treatment of each condition. To respond to this health and societal emergency, we established a network of academic institutions and non-academic partners to offer early-career researchers (ESRs) a high-quality international training program focused on the co-morbidity of pain and depression. We thus aimed to reach the overall objective of the HaPpY project which is to create an optimal environment for the training of ESRs to break the vicious cycle linking chronic pain and mood disorders. Accordingly, we developed the research project around 3 specific objectives: Firstly, we aimed to characterize the reciprocal relationship between chronic pain and mood disorders to improve diagnosis. For this purpose, we focused on the behavioral phenotyping of the comorbidity of chronic pain and mood disorders especially anxiety/depression in preclinical models and in patients. Indeed, for the first time, a side by side comparison of several preclinical models of chronic pain and stress/anxiety/depression is performed in different laboratories which provide the development and standardization of models and reinforce the reliability and reproducibility of studies across labs. One of the main reasons why preclinical targets identified in preclinical studies are not transposed into clinical trials is due to the basic nature of many of the preclinical tests, which simply examine helplessness or avoidance behaviors. We have developed new behavioral paradigms to improve the translatability of data. In parallel, clinical research ensures the development of cognitive-emotional tasks, unique to predict and diagnose the comorbidity of chronic pain and mood disorders by comparing behavioral outcomes, imaging datasets, physiological recordings and blood samples from well-characterized cohorts. Second, we aimed to better understand the underlying molecular, cellular and neuroanatomical mechanisms contributing to the comorbidity in preclinical models and in patients. The ultimate goal is to identify biomarkers for prediction/diagnosis and reveal new treatment strategies. Third aim is developing new treatment strategies. We adapted two strategies to optimize the use of already existing pharmacological/non-pharmacological treatments and to validate new preclinical targets, and provide novel insight for using brain stimulation facilitate early-stage translation of novel treatment strategies towards the clinic. Given evidence of sexual dimorphism of both chronic pain and mood disorders, all Individual Research Projects (IRPs) considers sex differences as a cross-cutting objective.

Data: CORDIS, © European Union