Overuse of antidepressants in older outpatients with Alzheimer's disease and associated disorders: an observational study.

Unlabelled: Forty per cent of French subjects over 65 years old with Alzheimer's disease and related disorders (ADRD) are chronically exposed to antidepressants, suggesting an overuse of these drugs. The main objective of our study was to estimate the prevalence of the overuse of antidepressants in this population and the factors associated with this.

Methodology: a single-centre, prospective, cross-sectional study carried out at the Bretonneau outpatient department between 1 December 2014 and 31 May 2015. All patients aged 70 and above, suffering from ADRD (according to DSM IV criteria) and currently being prescribed an antidepressant were eligible. "Overuse" was defined as off-label prescriptions or prescriptions that went beyond the recommended duration of treatment. This was assessed by the geriatrician in charge and validated by an expert committee, who were blind to the geriatrician's assessment.

Results: Fifty-four patients were included in the study (mean age: 82.9 years (± 5.4); 70.4% women; 60% with mild to moderate dementia). The main indication of antidepressant treatment was a major depressive episode (59.3%). The geriatrician could not reach a conclusion on overuse in 10 cases (18.5%). Inter-rater agreement between geriatricians and the expert committee was good (kappa coefficient: 0.73 [0.5-0.95]). Finally, 33 (61%) of these patients were overusing antidepressants: a third had an off-label prescription and two thirds had exceeded the recommended treatment duration. The only factor associated with this overuse was co-prescription of psychotropic drugs (p = 0.009).

Conclusions: the overuse of antidepressants is common in older patients with dementia, particularly overuse due to exceeding the treatment duration. This is significantly associated with co-prescription with another psychotropic drug, suggesting that this represents a more global problem of the overuse of psychotropic drugs.