The use of methylphenidate and the risk of suicide attempt: A population-based self-controlled case series study

Date of Approval
Application Number
Technical Summary

We will conduct a population-based self-controlled case series study including all individuals aged ≥6 years who received at least 1 prescription for ADHD medication in the CPRD database between January 1, 1995 to December 31, 2020. Our objective will be to compare the risk of suicide attempt among patients treated with ADHD medication in periods of exposure to ADHD medication versus unexposed periods. Participants who were continuously exposed to the drug will contribute to consecutive exposure risk periods. We will determine the duration of exposure in the study period and calculate incidence rates for suicide attempt events in each of the exposure risk periods. In our analysis, we will estimate the incidence rate ratios of our outcomes using conditional Poisson regression. We will estimate the adjusted IRRs and their 95% confidence intervals for exposure overall and for each predetermined exposure risk periods.

Health Outcomes to be Measured

Suicide attempt


Kenneth Man - Chief Investigator - University College London ( UCL )
Kenneth Man - Corresponding Applicant - University College London ( UCL )
Ian Wong - Collaborator - UCL School Of Pharmacy
Li Wei - Collaborator - University College London ( UCL )
Wallis Lau - Collaborator - University College London ( UCL )


HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation