In a double-blind, parallel-group controlled trial, we aim to measure the effect of two weeks of light therapy combined with the CPAP on compliance CPAP in patients with major depressive disorder.

Major depressive disorder (MDD) is a frequent and disabling psychiatric condition. Clinically, MDD is characterized by persistent depressed mood, loss of interest, loss of pleasure in daily activities, and sleep disturbance. The link between sleep disturbance and depressive symptoms is complex and bidirectional, but data from the literature suggest that treatment of sleep disturbance in patients with MDD is associated with a better prognosis and a reduction in the number of relapses.

Among sleep disorders, obstructive sleep apnea syndrome (OSAS) is a frequent comorbidity in MDD. The severity of OSAS correlates with the severity of depressive symptoms, and treatment of OSAS with continuous positive airway pressure (CPAP) can reduce daytime sleepiness and some depressive symptoms. Despite its efficacy, CPAP treatment is often poorly tolerated by patients, and compliance rates are often low, with discontinuation of treatment within the first 15 days of initiation, before it has had a chance to demonstrate its effectiveness. Light therapy is a non-invasive medical device that has been shown to rapidly reduce certain depressive symptoms, such as insomnia.

The aim of the study is to investigate whether the combination of two weeks of active light therapy with the introduction of CPAP can increase CPAP compliance at two weeks of treatment (D14) in patients with MDD and OSAS.

To this end, 130 patients with MDD (MADRS > 15) will be recruited and randomized to two intervention groups: one group receiving active light therapy combined with CPAP and one group receiving sham light therapy combined with CPAP. The study will take place in the patient's home. The company's service providers, accustomed to installing CPAP in patients' homes, will be responsible for delivering the light therapy glasses and actimetry watches at the end of the 2-week treatment period. A polysomnography recording will be acquired prior to treatment. Quality and compliance measurements are recorded by the CPAP machines and will be statistically analyzed.

The investigators hypothesize that the early combination of active light therapy and CPAP will enable changes in CPAP complance, MDD symptoms severity, and sleep quality in patients with MDD and OSAS.

Inclusion Criteria:

• Adults consulting at the MICHEL JOUVET unit, CH Le Vinatier, Bron
• Adults with a diagnosis of major depressive episode (DSM-V) and with a MADRS score ≥ 15
• Adults with a diagnosis of OSAS on ventilatory polygraphy or polysomnography (AASM 2017 criteria) requiring CPAP.

Exclusion Criteria:

• Refusal to participate.
• Pregnant and breast-feeding women
• Under guardianship or curatorship.
• Unstable psychiatric or physical pathology (e.g., hypomania, high suicidal risk) considered incompatible with the study by the investigators.
• Other psychiatric, neurologic or somatic conditions
• Contraindication to light therapy: retinopathy, retinitis pigmentosa, diabetic retinopathy, macular degeneration, glaucoma, recent eye surgery (less than 3 months).

patient wishing to choose a provider other than the protocol provider.

• Patient wishing to choose a device other than SEFAM's S-BOX or a mask other than the nasal mask at the time of introduction.
• Nasal obstruction.
• Refusal to use actimetry, refusal to use light therapy, refusal to use CPAP.

Sham light therapy consists of using a device similar to the active condition (glasses) but delivering a weakened version of the active light (addition of a filter and reduction of light intensity), emitting an intensity of 33 lux and a light spectrum (600 nm).