BACKGROUND: Direct-to-consumer advertising (DTCA) is legal in the US and New Zealand, but illegal in the rest of the world. Little or no research exists on the social welfare implications of DTCA. AIM: To quantify the total costs and benefits associated with both appropriate and inappropriate care due to DTCA, for the case of depression. METHODS: A cost-benefit model was developed using parameter estimates from available survey, epidemiological and experimental data. The model estimates the total benefits and costs (year 2002 values) of new appropriate and inappropriate care stimulated by DTCA for depression. Uncertainty in model parameters is addressed with sensitivity analyses. RESULTS: This study provides evidence that 94% of new antidepressant use due to DTCA is from non-depressed individuals. However, the average health benefit to each new depressed user is 63-fold greater than the cost per treatment, creating a positive overall social welfare effect; a net benefit of >72 million US dollars. CONCLUSION: This analysis suggests that DTCA may lead to antidepressant treatment in 15-fold as many non-depressed people as depressed people. However, the costs of treating non-depressed people may be vastly outweighed by the much larger benefit accruing to treated depressed individuals. The cost-benefit ratio can be improved through better targeting of advertisements and higher quality treatment of depression.
