Association between antidepressant prescribing and suicide rates in OECD countries: an ecological study

We have conducted an ecological study to assess the association between antidepressant prescribing and suicide rates using the Organisation for Economic Co-operation and Development (OECD) health data, making this the largest ecological study in recent times.

Data were derived for the years 1995-2008 from the OECD health data set. The residuals for all variables were adjusted for country and year within each country. These were then analysed to identify predictors of suicide rate. Pearson's rank correlation coefficient and linear regression model were employed to assess associations and identify significant predictors of suicide rate.

Suicide rate has significant positive correlations with antidepressant rates (p=0.031) and unemployment (p=0.028). It also has a significant negative correlation with inpatient psychiatric beds (p=0.039). The actual coefficients are less than ±0.16, indicating weak relationships. After adjusting for other variables, the only variable that is a statistically significant predictor of suicide rate is antidepressant prescribing (p=0.005, r²=0.09).

Our analysis using this large data set suggests a statistically significant, albeit weak positive, association between antidepressant prescribing and suicide rates.