Use of Selective Serotonin Reuptake Inhibitors - Validity of Self-Report versus Plasma Concentrations and Pharmacy Dispensations - A Cross-Sectional Analysis of the Norwegian Women and Cancer Study.

Self-reported current use of SSRI from the NOWAC questionnaires is highly valid and, according to plasma concentrations, perhaps even more so than pharmacy dispensations. Factors associated with discordance between information sources should be taken into account in the interpretation of future analyses which include SSRI-use in the NOWAC study.