The aim of this study is to validate the EmoDTx as a digital tool for mood monitoring in adult patients with unipolar depression. The study is prospective, multicenter, and observational, with a single-arm approach. The device studied, EmoDTx, is a mood-monitoring application that analyzes patients' facial expressions to assess their emotional state. The study aims to compare mood scores obtained via EmoDTx with those of standard depression questionnaires (MADRS, PHQ-9, BDI-II, HAMD-17, QIDS-SR16). It will also provide information on how patients feel about the use of passive monitoring software (without the active involvement of the patient) and how the feedback sent to patients can help in their care.

Participants who agree to take part in the study, during a selection visit, will be able to:

1. Install the software on a digital interface (smartphone, computer, etc.) and activate or deactivate it whenever they wish during the 8-week follow-up period.
2. Attend scheduled appointments at the center (a first appointment, then a second 4 weeks later, and a final at 8 weeks) to complete a series of questionnaires, be questioned by the doctor, and fill in other questionnaires on their own.
3. At home, answer questionnaires independently, 2 weeks and 6 weeks after the first appointment.
4. The application's feedback will be deactivated during the first 4 weeks and then reactivated during the final 4 weeks.
5. In parallel, an ancillary study will be conducted on 16 patients enrolled in EMC2FR who accepted and performed the video recording of their structured clinical interview following SCID-5-CV at baseline and 4 weeks.

Inclusion criteria:

1. Outpatients diagnosed with mild to severe unipolar disorder
2. Age ≥ 18 years old
3. Patients willing and able to participate (i.e willing to use the EmoDTx App and having the necessary technical equipment to use it)
4. Patients who read, write and understand French
5. Patients having signed the Patient Informed Consent

Exclusion criteria:

1. Patients hospitalized

2. Patients taking more than 75% of the maximal recommended daily dose of benzodiazepines

3. Patients taking more than 75% of the maximal recommended daily dose of antipsychotics

4. Patients taking more than 75% of the maximal recommended daily dose of neuroleptics

5. Patients who did not respond to 10 different pharmacological treatments

6. Patients who attempted suicide within the previous last 6 months and presenting with suicidal ideations

7. Patient presenting with bipolar disorders

8. Patients with a contra-indication to the device under evaluation:

   • Severe depression requiring hospitalization
   • Schizophrenic disorders according to DSM 5 classification
   • Major neurocognitive disorders according to DSM 5 classification
   • Illiteracy
   • Subject hospitalized in a healthcare or social institution for reasons other than biomedical research or is deprived of freedom by administrative or judicial decision or is placed under guardianship

9. Patients unable to read, write and understand French

10. Patients with no access to a smartphone or a computer with an internet connection

11. Patients who refuse to sign the Patient Informed Consent

12. Patients already participating in another interventional clinical study

Adult patients suffering from mild to severe unipolar depression