UCL School of Pharmacy


Longitudinal study on psychotropic medicine consumption published in The Lancet Psychiatry

23 November 2021

An analysis of global monthly sales data of psychotropic medicines between 2008 and 2019 showed that psychotropic medicine sales increased 4% annually, with the highest relative growth reported in upper-middle-income countries.

Disparities in access to psychotropic medicines remain a challenge across most of the world, especially in middle-income countries. In this longitudinal trends study by the Research Department of Pratice and Policy, we analysed monthly sales data of antidepressants, antipsychotics, tranquilisers, sedatives or hypnotics, and mood stabilisers between Jan 1, 2008, and Dec 31, 2019.

Abstract image of artificial neural networks in the brain

The global consumption of psychotropic medicine has increased from 28·54 DDD per 1000 inhabitants per day in 2008 to 34·77 DDD per 1000 inhabitants per day in 2019, corresponding to a 4·08% (95% CI 2·96–5·21) relative average increase annually. The average annual increase in sales of psychotropic medicine from 2008 to 2019 was highest in upper-middle-income countries (7.9%).

Our finding suggests that there is improved overall access to these medicines, but consumption rates of individual countries still vary substantially. In 2019, the highest sales of all psychotropic medicine classes were reported in northern America (167·54 DDD per 1000 inhabitants per day) and lowest sales in Asia (5·59 DDD per 1000 inhabitants per day).

Among the 17 countries with the lowest consumption in 2019, consumption of psychotropic medicine was the lowest in the Philippines (0·93 DDD per 1000 inhabitants per day). Such low DDD per 1000 inhabitants per day means that, on average, the consumption of psychotropic medicine is only sufficient for one patient per 1000 inhabitants per day in the Philippines.

Clearly, this is well below our current understanding of the epidemiology of mental health disorders. Analyses to capture any changes in consumption over time by geographical location and in relation to the prevalence of mental disorders, life expectancy, and health expenditure showed there was no evidence of a statistical association between changes in psychotropic medicine consumption and prevalence of mental illness. 

Disparities in psychotropic medicine consumption of countries can only partly be explained by geographical location and income. Greater efforts are needed to increase the availability of psychotropic medicines in countries with very low consumption, which is probably due to financial or cultural reasons as well as scarcity of trained health-care professionals to prescribe psychotropic medicines.

The study has been published in The Lancet Psychiatry. You can find the full text here: https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(21)00292-3/fulltext

Image credit: Artifical neural networks - www.istock.com