Use lay language.

According to the World Health Organization 1 death by suicide occurs every 40 seconds, leading suicide prevention to one of the public health priority.

BPD (Borderline Personality Disorder) is a common condition affecting 6% of the population.

This disorder is characterized by unstable emotions, unstable mood, difficulties with relationship and feer of abandonment.

Borderline Personality Disorder is also the psychopathology the most related to suicidal attempts.

Indeed, up to 50% of the patients admitted to hospital after a suicide attempt are diagnosis with a Borderline Personality Disorder

Negative interpersonal events (events occurring between two people) are known as the main stressor that trigger a suicidal attempt.

People with a Borderline Personality Disorder are highly sensitive to it.

Moreover, neuropeptides such as oxytocin (OXT), vasopressin and opioid are known to be involved in the regulation of the emotions, especially those linked to relationship.

The purpose of this study is to improve knowledge in suicidal behaviors.

After simulating an interpersonal stress, the evolution of plasma neuropeptides level (OXT, vasopressin and opioid) of patients with a BPD will be compared to healthy controls (HC).

Clinical data reflecting how the participant is feeling will be collected as well.

A dysregulation of the neuropeptides (OXT, vasopressin and opioid) could explain the dysregulation of the emotions of people with Borderline Personality Disorder.

Up to this date there is no other study measuring neuropeptides kinetics of patient with Borderline Personality Disorder after an interpersonal stress.

This task of stress is meant to reproduce what people with Borderline Personality Disorder suffer in their everyday life (ecological).

To reach this point, an imaginary interpersonal stress will be asked to be reproduced by the participants.

Neuropeptides concentrations and clinical data (fear, shame, anger, moral pain, compelling needs (suicidal and non-suicidal)) will be collected at different times (pre stress, post stress immediat, 5 minutes post stress,15 minutes post stress and 40 minutes post stress)

As copeptin ( fragment C terminal of the vasopressin) and vasopressin are found in stoichiometric concentration in the plasma as copeptin is more stable than vasopressin, plasma copeptin level will be used to reflect the one of vasopressin.

The hypothesis is that both the neuropeptide variation and clinical data before and after the interpersonal stress will be higher for the patient with Borderline Personality Disorder than healthy controls.

A correlation between clinical assessments and neuropeptides kinetics is expected. This study will help to identify inter-individual and contextual factors impacting neuropeptide's kinetics

Inclusion Criteria:

No specific inclusion criteria :

• If taking hormonal contraceptive: able to participate between the 3rd and 18th day after taking the contraceptive If not taking hormonal contraceptive: able to participate between the 5th and 12th day after the first day of the last period
• Able to understand the nature, purpose and methodology of the study
• Having signed the informed consent
• To be affiliated to a social security scheme

Specific inclusion criteria

Borderline Personality Disorder(BPD) :

- Clinical diagnosis of BPD using the SCID II (Structured Clinical Interview for DSM-IV-TR Axis II Personality Disorders)

Healthy controls:

- No personal history of psychiatric disorders (Axis I ) defined by the MINI International Neuropsychiatric Interview according to the DSM-5 criteria

Exclusion Criteria:

• Refusal of participation
• Subject protected by law (guardianship)
• Life time diagnosis of schizoaffective disorder or schizophrenia
• Pregnant or breastfeeding women
• Deprived of liberty Subject (by judicial or administrative decision)
• Exclusion period in relation to another protocol
• Having reached the maximum annual amount of allowances of € 4,500