Abstract
Randomized controlled trials indicate that antidepressant treatment increases the probability of remission in acute treatment of major depression, diminishes the frequency of relapse during continuation phase treatment and diminishes the risk of recurrence during maintenance treatment. As antidepressant coverage increases in the population, the benefits of antidepressant treatment should begin to translate into improved population health. However, adverse effects can also occur, as can unnecessary treatment. Monitoring the impact of antidepressant treatment on population health should be a priority for health surveillance. Quantitative description of the relationship between treatment provision and population health status will require the use of epidemiological models. A variety of such models have been reported in the literature. None of the existing models, however, are fully satisfactory.