Depression is one of the most common mental disorders, affecting nearly 10% of men and 20% of women worldwide. It is associated with a significant increase in mortality, mainly due to suicidal behavior. The Diagnostic and Statistical Manual of Mental Disorders (DSM) defines a Major Depressive Episode (MDE) by a combination of at least five different symptoms, with at least one depressed mood or loss of interest. MDEs can occur in isolation or as part of Major Depressive Disorder (MDD) or bipolar disorder (BD). Bipolar disorders affect 2% of the world's population and are defined by episodes of mania (Type I BD) or hypomania (Type II BD) alternating with episodes of depression and periods of remission.

Depression occurring whether in the context of BD or MDD is defined with the same clinical criteria. However, the pharmacological treatments are different in the two groups. In particular, antidepressants prescribed without a thymoregulator in bipolar patients can lead to a worsening of the episode, favoring suicidal behavior or a manic turn.

The average interval between the onset of BD symptoms and appropriate diagnosis is estimated to be approximately 7 years, which delays appropriate management and treatment and increases the risk of suicide.

Biological markers able to differentiate between the different types of depression were lacking before the advent of EDIT-B®; one of the main objectives of this research is to measure the clinical impact of the use of EDIT-B® in the short and medium term on the management of patients with BD and major depression. The health economic aspect will also be considered.

In total, 450 patients in two different groups (EDIT-B® group and control group) will be recruited over a study timeline of 24 months. Study participation is over 6 months with 4 visits.

Inclusion Criteria:

• Patients with a MDE, moderate to severe (DSM V criteria and MADRS score ≥19)

• Age between 18 and 65 years, gender indifferent

• Benefitting from health insurance coverage

• Having signed an informed consent and agreed to follow the study protocol to completion

• Patients for whom there is doubt regarding a bipolar disorder diagnosis, and/or presenting one or more of the following criteria:

  • More than 3 episodes of MDE in personal medical history
  • Psychotic symptoms
  • Family history of bipolar disorder
  • Onset of the first MDE before the age of 25
  • Atypical symptoms or mixed features during depressive episodes
  • Addiction
  • Personal history of suicide attempts
  • Resistance to antidepressants
  • Postpartum depression within 6 months of birth

Exclusion Criteria:

• Depression in the context of schizophrenia or autism spectrum disorder
• Patient with a well-established diagnosis of bipolar disorder
• Patients who is already receiving a mood stabilizer
• Severe somatic diseases that may interfere with the follow-up or associated with treatments at risk of secondary manic decompensation
• Neurodegenerative diseases
• Pregnant women