Antidepressant Usage in the Canadian Forces

Military Medicine, Feb 2006 by Gutschi, L Maria, Vaillancourt, Régis, Boddam, Randy

This study was performed to evaluate the use of antidepressant medications among Canadian Forces (CF) members. A retrospective chart review was undertaken at seven CF bases for members who received antidepressant medications during a 6-month period. Data were collected on doses, duration, and types of antidepressant drugs, indications for therapy, and prescriber characteristics. Indications were classified as depression, anxiety disorders (including post-traumatic stress disorder [PTSD]), or nonpsychiatric conditions. A total of 1,024 charts were reviewed. Antidepressant usage rates were similar across sites for depression and anxiety but differed for PTSD. Rates of PTSD demonstrated more variability than did rates of depression or anxiety disorders among CF members. Antidepressant therapy is also frequently prescribed for nonpsychiatric disorders. Indications for the use of antidepressants thus varied among CF members at different bases. Better detection and treatment of depression may be required in this population.

Introduction

A ntidepressant drug therapy is an effective treatment for various psychiatric conditions, such as depressive and anxiety disorders, as well as nonpsychiatric conditions, such as chronic pain, headaches, insomnia, and smoking cessation. Marked increases in antidepressant prescriptions have been documented in Canada,1,2 the United States,3 and Europe,4 reflecting both an increased willingness to use drug therapy and enhanced detection and diagnosis of depression in primary care.5

Depressive disorders are common in the industrialized world.6 The prevalence and incidence of mood disorders appear to be increasing in Canada, especially among young male subjects.7,8 The Canadian Forces (CF), which employs a large proportion of young male subjects, thus represent a population that may be at increased risk of depression by virtue of its demographic features. In fact, the CF 2002 Supplement of the Statistics Canada Canadian Community Health Survey found significantly higher rates of depression among CF members compared with the general population.9 The same survey found that the yearly prevalence of panic disorder was significantly higher among military members, although other anxiety disorders had prevalence rates similar to those for the civilian population.9

In the United States, previous studies found that prevalence rates of mood disorders in military populations were similar to those in civilian primary care populations10 and underdiagnosis of depressive disorders was equally common in the two sectors.10 Moreover, in the U.S. National Hospital Discharge Survey, the rate of hospital discharge for mental disorders among U.S. military personnel was remarkably similar to that noted among civilians during the same time period.11 Similar data are not presently available for Canada.

To date, few studies have been conducted to describe the usage patterns of antidepressants among military members. Such medications have many potential effects, both therapeutic and toxic, which can substantially affect an individual's functional ability. Because of the unique requirements and operational environments imposed on military members, it is possible that their usage of antidepressants differs substantially from that seen in the civilian population. Antidepressant usage may also allow inferences to be made regarding access to specialized psychiatric care among military members. Further investigation into their patterns of use is thus warranted.

This study was conducted to evaluate usage patterns for antidepressant drug therapy among CF members. In particular, additional information was sought regarding rates of use and indications for antidepressant therapy, as well as variability in usage between CF sites. Information gleaned from this study may also be helpful in monitoring overall usage of antidepressants in a military population.

Methods

Study Design and Subjects

Ethical approval for this study was obtained from an external ethics review board (Integrated Ethics, Montreal, Canada) on January 12, 2001. We then performed a retrospective chart review at seven CF bases. A convenience sample was obtained by using military pharmacy dispensing records. All Regular Force CF members who were dispensed an antidepressant drug between July 1 and December 31,2000, were included for analysis. Subjects were excluded from analysis if they met any of the following criteria: (1) if they were members of the Reserve Force (i.e., not a Regular Force member); (2) if their medical records were unavailable for review (e.g., because of deployment); (3) if they had been referred to the study base for specific clinical intervention only (i.e., overall care was being coordinated and provided at a different site); or (4) if they were military health professionals themselves.

Data Collection

Data were extracted from the medical charts by one of four pharmacist reviewers, with final data input coordinated by a single author (L.M.G.). To ensure internal validity, each pharmacist reviewer underwent training with the same author for the first 20 to 25 charts they reviewed. Inconsistencies were resolved through discussion between that author and the data extractor.