This study investigates how cocaine use and withdrawal affect sleep and circadian rhythms in individuals undergoing inpatient detoxification. Using wearable sleep monitors, actigraphy, questionnaires, and hormonal biomarkers, it aims to capture both objective and subjective changes in sleep across three key stages: active use, early withdrawal, and late withdrawal. The study is unique in its ability to explore sleep microstructure, the circadian system's role via melatonin and cortisol measurements, and the dynamic relationship between subjective sleep perception and objective sleep data. It also examines whether sleep quality may serve as a predictive marker of long-term withdrawal success.

Sleep disturbances are a common but poorly understood feature of cocaine use disorder, and may play a critical role in both relapse vulnerability and treatment outcomes. This interventional study aims to explore objective and subjective sleep patterns, as well as circadian regulation, across three distinct phases: during active cocaine use, early withdrawal, and late withdrawal. Participants will be individuals scheduled for supervised inpatient detoxification.

The study employs a multimodal assessment strategy:

• Ambulatory polysomnography using the Somfit® device will allow analysis of both macro- and microstructure of sleep across two nights per visit.
• Actigraphy will be used to capture precise temporal dynamics of sleep-wake rhythm over the course of the study.
• Subjective measures will include validated self-report questionnaires on sleep quality, insomnia severity, sleepiness, fatigue, and sleep perception.
• Urinary biomarkers (free cortisol and 6-sulfatoxymelatonin, collected 5 times/day) will provide data on circadian rhythm integrity, enabling exploration of the role of circadian dysregulation in sleep disturbances.

A key originality of the study lies in its ability to dynamically assess the relationship between subjective and objective sleep parameters and to explore the circadian contribution to sleep disruption in cocaine users. Furthermore, by following patients through early and late withdrawal, the study will investigate whether sleep parameters could serve as predictive markers of long-term withdrawal success, offering potential targets for future therapeutic interventions.

Inclusion Criteria:

• Male or female, aged 18 years or older
• Meeting DSM-5 criteria for cocaine use disorder
• Positive urine drug screen for cocaine
• Scheduled for inpatient supervised cocaine detoxification within the next four weeks
• Covered by a national health insurance plan or social security system
• Have a valid, personal means of contact (telephone or email address) enabling remote follow-up at 6 months.

Exclusion Criteria:

• Current diagnosis of opioid use disorder or other psychostimulant use disorders (e.g., amphetamines, methamphetamines, cathinones, methylphenidate)
• Unstable psychiatric disorder or somatic illness deemed incompatible with study participation by the investigator
• Current treatment with methylphenidate, modafinil, solriamfetol, melatonin, pitolisant, naltrexone, or bupropion
• Patients under legal guardianship
• Pregnant or breastfeeding women: a pregnancy test will be performed prior to inclusion for women of childbearing potential
• Individuals deprived of liberty by judicial or administrative decision

Patients with cocaine use disorder seeking hospitalization for withdrawal