The Cannabinoide Hyperemesis Syndrom (CHS) is defined as a recurrent syndrome of intractable vomiting that occurs in chronic cannabis consumers. The diagnosis is linked to clinical criteria only. The physiopathology of CHS is unknown and we observe an increase of cases with this syndrom since 2016 (Schreck et al., 2018).

The aim of this study is to investigate the involvement of exogenous cannabinoids concentrations in chronic cannabis users in the occurrence of CHS.

Inclusion Criteria:

• Subjects without protection by a legal regime (guardianship, trusteeship)
• Subjects affiliated to an appropriate social security system
• Subjects must sign an informed consent form

Inclusion Criteria for Group 1:

- Subjects must have the CHS diagnosis confirmed

Inclusion Criteria for Group 2:

- Subjects must be chronic cannabis consumers and never had CHS

Exclusion Criteria:

• Subjects must not have addictive comorbidities or psychoactive substance abuse (except alcohol and tabacco)