Fig. 1: Top: Total estimated prescriptions dispensed in Ontario for hormone replacement therapy (HRT: oral and transdermal estrogen monotherapy and estrogen–progesterone combination therapy) and serotonergic antidepressants (SAs: citalopram, fluoxetine, sertraline, fluvoxamine, paroxetine, venlafaxine, nefazadone and trazadone) to women 45–65 years old, from January 2001 to June 2003. [Source: IMS Health Canada.] A consistent downward trajectory in the number of HRT prescriptions and a simultaneous increase in the number of SA prescriptions occurred after July 2002, when results indicating potential harmful effects of HRT were published. Bottom: Linear regression models of the number of prescriptions against time, for each prescription type (HRT and SA) and for each time period (11 months before and 11 months after July 2002). The predicted slopes (β ± standard error [prescriptions/day]) are shown, accompanied by a test of the null hypothesis: β = 0. There was no statistically significant longitudinal trend during the 11 months before July 2002; however, during the period following July 2002, there was a statistically significant decrease in HRT utilization that coincided with an increase in SA utilization. Comparison of the regression models (HRT v. SA prescriptions) revealed a statistically significant change in the prescription pattern of both agents after the medical scrutiny of HRT usage (β: –25.6 v. 33.2, p < 0.001). *p < 0.001.