1/ What led you to develop this research?

In 2018, we conducted a first study on the excess mortality of individuals with mental disorders, which showed a reduction in life expectancy at the national level, reaching an average of 16 years for men and 13 years for women, as well as a premature mortality rate quadrupled compared to the general population. These descriptive elements called for explanations as to the potential causes of this overwhelming finding, which suggests that people living with a mental disorder are confronted with strong health inequalities. It has therefore led us to try to objectify on a large scale the possible difficulties faced by this population in their somatic care pathways. The first step in this direction was to document potential disparities in the use of routine somatic care by individuals who were treated for a severe mental disorder (psychotic or bipolar disorder) compared to the general population. This study is the result of the project "Comorbidities and somatic care pathways of individuals treated for a mental disorder" (Colchique, Comorbidités et parcours de soins somatiques des personnes suivies pour un trouble psychique), financially supported by the The French National Union of Friends and Families of Patients with Mental Disorders (Union Nationale de Familles et Amis de Personnes Malades et/ou Handicapées psychiques, UNAFAM).

2/ What are the main markers of inequality of access and use of care for this population that you identify in your study?

Data from the National Health Data System (SNDS), which we mobilized in this study, show a lower use of preventive healthcare (particularly for cancer screening) and standard specialist healthcare (dental, gynecological, ophthalmological care) among individuals treated for a severe mental disorder, despite a higher prevalence of the main chronic disorders than in the general population. Our results also show a higher number of avoidable hospitalizations, despite more frequent contacts in general medicine. These findings are all the more striking as they are observed when comparing the population treated for a severe mental disorder with controls, not treated for this type of disorder, presenting similar sociodemographic characteristics (at least for those that were available in the database used), and after adjustment for their main clinical and living environment characteristics. This adjustment is important because it underlines the very own effect of the presence of a severe mental disorder and demonstrates that the greater socio-economic vulnerability of the individuals treated for such a disorder is not sufficient to explain the disparities found, although this is a hypothesis often put forward.

3/ How to improve this situation?

Our study underlines the difficulties of the health system in responding satisfactorily to the specific needs of people living with a severe mental disorder. It supports the necessity to develop specific measures to increase their use of healthcare, to assist health professionals to ensure they take into account their needs for somatic care, and encourage the treatment of their physical health (for example, via the development of therapeutic education programmes). Qualitative studies aimed at better documenting the main causes of the disparities found on a national scale (factors linked to individual behaviours such as social isolation or difficulties in perceiving pain; factors linked to the health system such as poor integration of mental and physical healthcare, poor attribution of somatic symptoms to the mental disorder, over-complexity of the system, etc.) will complete our first findings. Thus, we are now developing a joint research project which, through the illustrative example of people treated for cancer, aims to better characterize the difficulties in the care pathways of individuals living with severe mental disorders in order to identify levers linked to the health system to reduce their occurrence (Project "Cancers for individuals treated for a mental disorder: which difficulties in care pathways?" (Canopy), funded by the French National Cancer Institute (INCA, Institut national du cancer) until 2022).