What drives the rise of antidepressant consumption? Evidence from Switzerland

Antidepressant (AD) consumption has been steadily increasing in the last decade in most countries. The explanations suggested by researchers for this increment are still under scrutiny. This study attempts to identify the determinants of AD consumption by exploiting small area variations from Switzerland between 2003 and 2014. We observe that two specific drugs - Citalopram and Escitalopram - within the Selective Serotonin Re-uptake Inhibitors (SSRI) category are mainly responsible for the increasing trend in AD consumption. Socio-economic, demographic, cultural, and geographical characteristics of the area are included in multiple regression models with random and fixed effects of AD consumption per capita. While most of these factors contribute to explain cross-area variations in AD use, they provide little explanation for the temporal trend in overall AD consumption. Conversely, we find that the time trend in AD consumption is explained at least partially by the density of prescribing physicians. More precisely, generic AD turn out to be positively associated with adverse local economic conditions, while branded AD are negatively associated with adverse economic conditions and positively related to the presence of neurologists and psychiatrists in the area. This may suggest that generic AD drugs are more likely prescribed in accordance to need, whereas branded AD are more likely to respond to preferences and financial incentives affecting suppliers.