Dependence on prescription benzodiazepines and Z-drugs among young to middle-aged patients in France.

Background: Benzodiazepines (BZD) and nonbenzodiazepines hypnotics (z-drugs) are recognized as one of the most widely prescribed medications in the world.

Objectives: The purpose of the study was to assess the BZD and z-drugs dependence in young to middle-aged outpatients who were taking BZD/z-drugs on a chronic basis, and to characterize their profile.

Methods: This is a forward-looking cross-sectional epidemiological study. Data were collected through a semi-structured interview within a network of partner pharmacies from the Nantes area, in France. All data were obtained exclusively through patients' declarations. 212 patients (19-64 years old) were included: they were considered dependent when they answered positively to at least three items of the DSM IV. A multivariate logistic regression and a principal component analysis (PCA) were carried out to determine their profile.

Results: Almost half of the patients met criteria for BZD/z-drugs dependence. The risk to develop BZD/z-drugs dependence is significantly associated with psychiatric history and with the quantity of BZD/z-drugs that is taken. A two factor concept of dependence could be identified according to the PCA: one axis with items of "tolerance" and "long term administration or higher doses", and a second axis with "concerned by treatment" and "somatic consequences". Conclusions/Importance: Among this BZD/z-drug dependent population, the two axes identified in the PCA represent two profiles of dependence: being in positive conditioning or suffering from negative consequences. Clinicians need to know them: these two clinical profiles may have an influence in terms of decision-making, especially to manage discontinuation.