[Overuse of antidepressant in older outpatients with Alzheimer disease and associated disorders: an observational study].

Forty per cent of French subjects over 65 years old with Alzheimer's disease and related disorders (MATA) are chronically exposed to antidepressants suggesting an overuse of these drugs. The main objective of our study was to estimate the prevalence and factors associated with overuse by antidepressants in this population. Single-center, prospective, cross-sectional study carried out at the Bretonneau Day Hospital (HDJ) between December, 1st 2014 and May, 31 2015. Consecutive patients with ≥70 years of age, suffering from MATA (according to DSM IV criteria) and current prescription of antidepressant were eligible. Overuse was defined by off-label prescriptions or prescriptions beyond the recommended duration of treatment. It was assessed by the geritrician in charge and validated by an expert committee, blind from the geriatrician's assessment. Fifty-four patients were included in the study (mean age 82.9 years (+/- 5.4), 70.4% of women, 60% with mild to moderate dementia). The main indication of antidepressant treatment was a major depressive episode (59.3%). The geriatrician could not deal with overuse for 10 cases (18.5%). Inter-rater agreement between geriatricians and expert committee was good (kappa coefficient 0.73 [0.5-0.95]). Finally 33 (61%) of these patients had overuse of antidepressants: 1/3 had an off-label prescription and 2/3 had an exceeded treatment duration. The only factor associated with this overuse was coprescription of psychotropic drugs (p=0.009). Antidepressant overuse is common in demented older outpatients, especially overuse due to exceeded treatment duration. It is significantly associated with coprescription with another psychotropic drug, suggesting that it fits into a more global problem of overuse in psychotropic drugs.