Description

Depression is a mental health disorder characterized by persistent sadness, loss of interest in previously enjoyed activities, and a marked decrease in energy. It can present in different forms, including depressed mood, depressive syndrome, or major depressive episode (MDE), which is the best-defined form in international medical classifications. The diagnosis of a Major Depressive Episode (MDE) relies mainly on clinical assessment. However, standardized tools such as the Patient Health Questionnaire-9 (PHQ-9), the Montgomery-Åsberg Depression Rating Scale (MADRS), the Beck Depression Inventory-II (BDI-II), the Hospital Anxiety and Depression Scale (HADS), and the Hamilton Depression Rating Scale (HDRS) are also used. These tools were designed and validated to support and guide diagnosis, in both clinical and research settings. They make it possible to measure symptom severity and to monitor it over time. MDE is defined by several factors, including core symptoms (e.g., depressed or irritable mood, loss of interest), negative thoughts, and severity and duration criteria (a minimum number of symptoms present during the past 15 days).

Worldwide, approximately 3.8% of the population (280 million people) suffers from depression. The prevalence is 5% among adults (4% of men and 6% of women) and 5.7% among people over 60 years of age. In France, an estimated 15 to 20% of the general population is affected by MDE, with a prevalence of 12.5% among 18- to 85-year-olds in 2021. Several severity grades of MDE are distinguished; moderate to severe levels are estimated to account for 95% of all cases, regardless of sex. However, depression is more frequent in women (11.4% versus 5.3% in men).

A first MDE may sometimes resolve within six to nine months without specific intervention, but pharmacological treatment is often recommended for moderate to severe cases.

After eight weeks of treatment, about one third of patients achieve complete remission, another third achieve partial remission, and the last third do not respond to treatment.

Because of its individual and societal consequences, depression is a major public health problem, generating high costs related to absenteeism as well as to the overall care of affected individuals. Indeed, depression impairs the daily functioning and the social and professional relationships of those affected, and is associated with very frequent suicidal behaviors in these individuals. At the societal level, the direct and indirect costs associated with depression-related absenteeism were estimated at US$210 billion in the United States in 2010. In France, mental health is now a priority, with health insurance spending exceeding €23 billion in 2023. Including indirect costs, total spending related to psychiatric illness could exceed €163 billion, with depressive and anxiety disorders among the leading causes of years lived with disability.

Depression is a disorder marked by recurrence, with the risk of depressive episodes increasing after each episode. This risk is mainly predicted by the number of previous episodes: more than 50% of individuals develop a second episode after the first. After two episodes, this rate rises to 70%, and it reaches 90% after three episodes. The management of depression is multidisciplinary and varies according to the severity of the disorder. Pharmacological treatment is generally recommended for moderate to severe cases. Initial antidepressant treatment lasts 6 to 12 weeks. The French National Authority for Health (Haute Autorité de Santé, HAS) recommends assessing treatment efficacy between 4 and 8 weeks before starting a second, continuation phase of 4 to 9 months. During this second phase, the treatment may be adjusted or changed depending on the patient's progress.

It is not uncommon for the potential adverse effects of prescribed antidepressants to be observed before the benefits of treatment, which must be anticipated and clearly explained to the patient to promote adherence to therapy. Indeed, compliance with treatment recommendations for depression significantly reduces the risk of relapse, highlighting the importance of adherence to pharmacological treatments. Adequate adherence to therapeutic guidelines is crucial to improve clinical outcomes and achieve remission of symptoms. The literature indicates that adherence rates are generally low and tend to decline over time, which is associated with an increased risk of relapse and higher healthcare costs.

In France, geographic disparities in the distribution of psychiatrists, with a strong concentration in Île-de-France compared with other regions, limit access to care for patients requiring their expertise. General practitioners have become the main recourse for patients with mental disorders or psychological distress. Indeed, an estimated 15 to 40% of general practitioners' active patient lists present with a mental disorder or psychological distress. However, although trained in the management of somatic conditions, general practitioners sometimes lack the specific skills to recognize, support, and treat psychiatric disorders in depth. This often results in limited management and heavy prescription of psychotropic drugs. An estimated 90% of first-line antidepressant prescriptions come from general practitioners, yet follow-up remains insufficient. For example, the first medical follow-up after a prescription often occurs late, with a median of 27 days, whereas it is crucial for assessing efficacy, tolerability, adherence, and suicide risk. Since March 1960, France has had a sector-based psychiatric policy aimed at guaranteeing a minimum level of territorial provision, with a relatively dense geographic distribution. However, this system appears to have reached its limits, and digital solutions now represent an innovative lever to address this major public health issue. Digital mental health tools offer technological and practical means to overcome barriers related to access to care, specialized diagnosis, and personalized management. Digital phenotyping of patients is essential to move psychiatric care toward a precision medicine approach.

In the literature, digital solutions such as mobile applications have demonstrated effectiveness in improving mental well-being and reducing symptoms of depression and anxiety. Indeed, several systematic reviews and meta-analyses have reported the efficacy of app-based mHealth interventions for managing anxiety and depression symptoms, with small to moderate effects compared with control groups. Although studies support the effectiveness of mobile applications in managing mental disorders, most focus on stand-alone digital therapies, without fully integrating care coordination. Yet by facilitating information exchange between patients and healthcare professionals, these telemonitoring tools can help provide and improve access to personalized care. The recent health crisis has fostered the emergence of innovative digital health approaches, highlighting the importance of the digital transformation of care pathways. It has shown that this transformation could improve coordination among healthcare professionals and overcome traditional barriers to access to care, such as geographic distance. In mental health, quality follow-up and good coordination among healthcare professionals are essential to ensure optimal patient management. Telemonitoring could play a key role by facilitating this coordination and patient follow-up through alerts adapted to each patient's situation. These qualified data, integrated through dedicated solutions, make it possible to adjust each patient's specific care in real time according to the needs and circumstances that triggered the alert. However, in France, there is currently no telemonitoring device in mental health reimbursed by the French National Health Insurance (Assurance Maladie). Currently available digital solutions, such as Doctolib, Maiia, Weda, or Qare, are limited to practice-management tools designed to facilitate consultations for practitioners, without any innovation aimed at improving the quality of care. Likewise, existing self-monitoring or psychological support solutions, such as MonSherpa and Jardin Mental, as well as the psychological support services offered by supplementary health insurers such as Alan or Teale, do not have an integrated telemonitoring system dedicated to psychiatry. With its innovative solution ThIA Suivi, ThIA Santé Mentale aims to fill this gap by offering the first digital telemonitoring device specifically dedicated to mental health, fully integrated into a care pathway supervised by healthcare professionals. In addition to its potential medico-economic impact, this device is part of a sustainable-care approach, aiming to optimize patient management while reducing the risk of relapse. This clinical investigation therefore aims to evaluate the clinical efficacy of ThIA Suivi in the management of depressed patients followed by a psychiatrist.