Association between statins and the risk of suicide attempt, depression, anxiety, and seizure: A population-based, self-controlled case series study

Background: Risk of suicide attempt, depression, anxiety and seizure and the association with statins is an ongoing debate. We aim to investigate the association between statins and the above neuropsychological out-comes, in specific pre-and post-exposure time windows.Methods: We identified patients aged 40-75 years old who were dispensed a statin between January 1, 2003 and December 31, 2012 from the Hong Kong Clinical Data Analysis & Reporting System (CDARS), an electronic medical records database. Patients with new onset of suicide attempt, depression, anxiety and seizure were derived from the original dataset separately, in a self-controlled case series study design. A non-parametric spline-based self-controlled case series model was built to measure continuous changes of risk. Results: We identified 396,614 statin users. The risk of each outcome was elevated prior to statin initiation with incidence rate ratios of 1.38 (95 % CI, 1.09-1.74) for suicide attempt, 1.29 (95 % CI, 1.15-1.45) for depression, 1.35 (95 % CI, 1.19-1.53) for anxiety, and 1.45 (95 % CI, 1.21-1.73) for seizure. The incidence rate ratios remained elevated after the initiation of statins during the first 90 and 91-365 days after statin prescription and decreased to the baseline level after 1 year of continuous prescription. Limitations: CDARS includes prescription data but not adherence data, which could lead to misclassification of exposure periods.Conclusions: Our study does not support a direct association between statin use and suicide attempt, depression, anxiety and seizure, whose risks could be explained by cardiovascular events, for which statins were prescribed.