Since the COVID-19 pandemic, mental health disorders have increased significantly, particularly among young people. In France, the proportion of young people aged 18 to 25 suffering from depression almost doubled between 2017 and 2021. This phenomenon particularly affects students, who are already identified as being at greater risk of mental health disorders than the general population. Medical students seem to be particularly vulnerable: in 2021, a national study showed very high rates of depression and suicidal thoughts in this population. The main factor associated with depression was the feeling of financial hardship.

Students often face multiple forms of insecurity. Financially, they have limited resources and struggle to cover their basic needs such as housing, food and healthcare. Socially, many experience significant isolation, particularly when they are away from their families or under pressure from their studies. All of this has a significant impact on their mental health. Unfortunately, many students do not seek help due to lack of time, resources, or awareness of support services. The 2021 study showed that only one-third of medical students suffering from depression received appropriate treatment.

The aim of our study is to assess the impact of precariousness on the onset of psychiatric disorders and on the use or non-use of healthcare services.

Our study will involve nearly 45,000 students from PSL and UPC universities. It is based on a longitudinal cohort (via questionnaires) over three years. The aim is to identify precisely the different aspects of student precariousness (housing, transport, isolation, economic difficulties, etc.) and their link with psychological distress. The study will measure the extent of the phenomenon and identify modifiable factors that could be targeted by preventive measures. The results will enable us to better target preventive measures and propose concrete solutions to improve students' well-being and promote their success.

The COVID-19 pandemic has led to an increase in depression, particularly among young people. The French health barometer, conducted every 4-5 years by Santé Publique France (SPF), found that the prevalence of major depressive episodes (MDE) among 18-25 year olds doubled (from 11.7% to 20.8%) between 2017 and 2021. There has also been an increase in suicidal thoughts and suicide attempts. Among students, data from the 2016 Student Life Observatory (OVE) found a higher prevalence of CDE and suicidal thoughts among students than in the general population of the same age. Among the factors associated with the risk of EDC, experiencing significant financial difficulties was the main one[4]. Among medical students, a national study conducted in 2021 found that the prevalence of depression and suicidal thoughts was much higher than in the general population of the same age. Financial difficulties were also the main factor associated with the risk of depression. Indeed, students are a population that is particularly vulnerable to precariousness due to several factors. Economically, they often have limited incomes, depending on parental support, insufficient grants or precarious jobs. This exposes them to difficulties in meeting their basic needs such as housing, food and healthcare. Socially, isolation can exacerbate their situation, especially when they are far from their family network or under pressure from their studies. In addition, high academic demands, combined with unstable living conditions, impact their mental health and can contribute to the development of psychiatric disorders, which often go untreated due to a lack of affordable and accessible resources. International students are even more vulnerable due to language and administrative barriers and limited access to local support services. This multidimensional precariousness highlights the need for comprehensive support for this population, even though students are unlikely to seek professional help. In the 2021 survey, only 32% of medical students suffering from depression received adequate care. If we want to improve the health of medical students, we must not only treat disorders, but also prevent them from occurring by helping students strive for a state of well-being. In terms of prevention, the Haute Autorité de Santé (HAS) distinguishes between three levels: primary prevention, which acts upstream of the disease (on risk factors); secondary prevention, which acts at an early stage of its development (screening); and tertiary prevention, which acts on complications and the risk of recurrence.

The objectives of the study are to identify and quantify the modifiable predictive and moderating factors explaining students' psychological distress that could give rise to (primary) prevention actions by studying the various components of precariousness (housing, transport, study conditions, social isolation, grants, etc.). It also aims to study the impact of the various components of precariousness on the use and non-use of healthcare (screening and treatment, secondary and tertiary prevention).

The data will be entered directly by participants on the SKEZIA platform (https://skezi.eu/) (a solution developed by SKEZI) co-founded by AP-HP and Paris-Cité University, and will be hosted on HDS-approved servers.

Main objective:

The objective is to explore the impact of precariousness on the risk of characterised depressive episodes and the use of healthcare among PSL students (17,000 students) and UPC health faculty students (28,000 students).

Primary outcome measure:

The study will assess the 12-month prevalence of:

• characterised depressive episodes (using the Composite International Diagnostic Interview Short-Form (CIDI-SF)) and suicidal ideation in the same way as SPF and OVE;
• use of healthcare services, which will be measured in a similar way to the OVE survey and the medical student survey.

Precariousness will be assessed by the question: 'Would you say that you are currently experiencing financial difficulties?'

Secondary objectives and evaluation criteria:

The secondary objectives are to :

• evaluate the prevalence of :
• anxiety, which will be assessed using the GAD7;
• eating disorders, which will be assessed using the SCOFF;
• alcohol addiction, which will be assessed using the AUDIT, and cannabis addiction, which will be assessed using the CAST;
• burnout, using the student version, which will be assessed using the MBI-SS for pre-clinical or healthcare students and the MBI-HSS for externs and residents,
• dropout, which will be assessed by a single question as in the CNA-CORE survey,
• insomnia, which will be measured by the Insomnia Severity Index (ISI),
• loneliness, which will be assessed using the UCLA 3 items,
• harassment,
• discriminatory treatment,
• and quality of life (WHOQOL);
• identify and quantify modifiable predictive and moderating factors explaining students' psychological distress that could lead to (primary) prevention measures = by studying the various components of precariousness (housing, transport, study conditions, social isolation, grants, etc.),
• study the impact of the various components of precariousness on the use and non-use of healthcare (screening and treatment, secondary and tertiary prevention). This will be assessed using questions on the renunciation of healthcare and its causes.

Inclusion Criteria:

• Student enrolled at Paris Sciences et Lettres University (PSL, 17,000 students) or the Faculty of Health Sciences at Paris Cité University (UPC, 28,000 students),
• Aged 18 or over,
• Fluent in French,
• Affiliated to a health insurance.

Exclusion Criteria:

• Applicants under the age of 18,
• Not enrolled at PSL universities or the UPCS Faculty of Health,
• Insufficient level of French.

All students enrolled at Paris Sciences et Lettres University or the Faculty of Health Sciences at Paris Cité University.