The current context of the Covid-19 health crisis leads to an over-solicitation of health systems, with hospital staff in the front line. These personnel are undergoing high levels of stress, an alteration of their life rhythm, but also of their health status and quality of life at work. In addition, night work, through the disruption of circadian rhythms, has consequences on physical and mental health. The more frequent worsening of the condition of certain patients at night increases the burden and responsibilities of night staff. Increasing the use of psychoactive substances (SPAs) can become a solution for managing stress, work rhythms, sleep disorders and their consequences. This self-medication behaviour is not without risks, neither for staff nor for patients.

The ALADDIN study is a project made up of 2 waves of questionnaires - one during and the other after the Covid "hospital" crisis - filled in by the hospital night staff of AP-HP. This project will assess the impact of the Covid-19 epidemic on the quality of work life, mental health disorders, post-traumatic stress and substance use of hospital night staff.

The main objectives of this study is to evaluate the prevalence of psychoactive substance consumption among the night shift healthcare workers of the AP-HP and to describe the participants' quality of working life.

Methods The study is prospective study using an online self-completed questionnaire. The questionnaire was elaborated on the basis of the validated scales ASSIST (Alcohol, Smoking, and Substance Involvement Screening Test), AUDIT-C (Alcohol Use Disorder Test, shortened version) and HAD (for anxiety and depression) and on qualitative interviews conducted among care staff working the night shift.

The questionnaire will be completed at t0 (baseline) and 18 months after. This study will provide data on the consumption psychoactive substances by night hospital workers adn their quality of working life. It will also allow us to compare their consumption with the general population, and to describe the risk factors influencing the consumption.

Inclusion Criteria:

- hospital workers at APHP, working at night or night and day alternance (working at least 3 hours between 9 p.m and 6 a.m, 2 times a week)

Exclusion Criteria:

• Hospital workers working during the day
• Workers working less than 3 hours a night two time a week
• Doctors

As night workers are more prone to impaired health and to addictions, the study focuses on hospital night workers who represent a population particularly at risk.