The effect of local growth in antidepressant consumption on mental health outcomes

Despite growing skepticism regarding the efficacy of antidepressants, global consumption is increasing at an unprecedented path with unknown implications for society. We estimate the causal effect of this increase on mental health outcomes using an IV strategy that exploits detailed drug sales data from Switzerland between 2002 and 2014. Our instrument, a modified version of the popular shift-share instrument, relies on the national growth in antidepressant sales for pharmaceutical companies (the shift) - mainly due to product innovation - and assigns it locally using regional non-antidepressant market shares. Our estimates show that an increase in antidepressants sales does not significantly affect suicide rates but cause an increase of hospital admissions for mental disorder and for depression. The causal effects prove to be resistant to several robustness checks.