Objective: To assess the prevalence of antidepressant use with respect to age, gender, and time during a 5-year period from 1993 to 1997.
Design: A retrospective, population-based study in which data regarding a cross-sectional series of annual antidepressant use were obtained from administrative claims and census databases for more than 1.4 million older persons during calendar years 1993 through 1997.
Participants: All residents of Ontario aged 65 or older.
Main outcome measures: Changes in the prevalence of antidepressant users as a function of age group, gender, and time.
Results: A general, positive, linear trend in the prevalence of antidepressant users with increasing age group was consistently detected regardless of gender and year assessed (P < .001 for both genders and all years). The age-adjusted relative risk of women being dispensed an antidepressant relative to men was significantly higher during each year but seemed to decrease slightly over time: 1.74 (95% CI, 1.72-1.76) in 1993 and 1.65 (95% CI, 1.63-1.67) in 1997. The multiple linear regression model revealed significant relationships between the prevalence of antidepressant users and increasing age group, female gender, and increasing year of assessment (P < .001 for each variable). The prevalence was observed to range from a low of 5.6% in 65 to 69-year-old men in 1993 to a high of 17.2% among 85 to 89-year-old women in 1997.
Conclusions: Our findings reveal that the prevalence of antidepressant users is dynamic and is significantly and independently associated with age, gender, and time of assessment.