The objective of our study is to describe the prevalence of insomnia during active consumption and hospitalisation for detoxification, and its influence on relapses at 3 and 6 months in drug-dependent patients.

We conducted a prospective study of drug-dependence inpatients admitted to the hospital detoxification unit between June 2008 and November 2012, and performed psychiatric follow-up on an outpatient basis over the six months following discharge. Insomnia prior to admission was measured by clinical interview from the patient concerning sleep habits, and during hospital stay using a sleep log filled out by nurse team. Demographic, clinical and diagnostic variables were recorded and a structured clinical interview (SCID) was conducted to assess psychiatric diagnoses. Relapse was deemed to be renewed use of the substance that brought about admission, which was assessed by alcohol testing and/or urinalysis.

We included 434 patients. Insomnia during consumption was reported by 64.3% of patients and 66.1% reported insomnia during hospital stay. Of the patients with preadmission insomnia, 68.3% relapsed at 3 months from discharge, as did 71% of patients with insomnia during hospital stay. Patients who relapsed at 3 months of follow-up showed significantly greater sleep initiation dysfunction prior to and during hospitalisation. Of the patients with preadmission insomnia, 69.2% had relapsed at 6 months from discharge. Patients who relapsed at 6 months of follow-up showed significantly greater sleep initiation dysfunction and global insomnia prior to and during hospitalisation.

Sleep disorders should be study as a prognostic factor in drugdependent patients.