Use of benzodiazepines and selective serotonin reuptake inhibitors in middle-aged and older adults with anxiety disorders: a longitudinal and prospective study.

OBJECTIVE: The purpose of this study was to examine the use of benzodiazepines (BZs) and selective serotonin reuptake inhibitors/selective norepinephrine reuptake inhibitors (SSRIs/SNRIs) over nine years of follow-up in middle-aged and older adults with diagnoses of panic disorder with or without agoraphobia, social phobia, or generalized anxiety disorder.

SETTING AND PARTICIPANTS: Participants in this study were enrolled in the Harvard/Brown Anxiety Research Project (HARP). HARP is a naturalistic, longitudinal, multisite study of adults with anxiety disorders who are recruited from psychiatric settings. The analytic sample consisted of 51 participants with anxiety disorders who were 55 to 70 years old at baseline and a younger cohort of 211 participants added for comparative analysis.

DESIGN: The authors examined patterns of medication use (BZs and SSRIs/SNRIs) in participants with anxiety disorders as they aged, by assessing the proportion of participants taking these medications using generalized estimating equation modeling.

MEASUREMENTS: The present data were derived from the structured diagnostic interview administered at enrollment using a combination of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Third Edition-R Non-Affective Disorder, Patient Version, Research Diagnostic Criteria Schedule for Affective Disorders-Lifetime, and subsequent follow-up interviews over a nine-year period using the Longitudinal Interval Follow-up Evaluation-Pharmacia & Upjohn to assess the weekly course of disorders to indicate syndrome severity and document medication use by specific type and dose on a weekly basis.

RESULTS: Findings showed that rates of BZ use were high among both the older (53% at baseline) and the younger (57.4%) age groups and did not significantly decrease over time, after controlling for time in episode of their anxiety disorders. There was a statistically significant increase in SSRI/SNRI use over time in both groups. At the beginning of the study, 18% of the older group and 21% of the younger group were using SSRIs/SNRIs; however, at the end of the study, the rates increased to 35% and 43%, respectively.

CONCLUSIONS: Although there was an increase in SSRI/SNRI use in older participants with anxiety disorders over the course of study, at nine years of follow-up, only 35% of participants were utilizing SSRI/SNRI medication, while more than one-half of the same participants were continuing to use BZs. To the authors' knowledge, there are no randomized clinical trials that have addressed comparative efficacy and safety of BZs and SSRIs/SNRIs in this population. However, there is documented evidence of adverse effects of chronic BZ use and the risk of developing dependency in older populations.