A 2-year prospective analysis of insomnia as a mediator of the relationship between androgen deprivation therapy and perceived cognitive function in men with prostate cancer

Abstract

Background: Androgen deprivation therapy (ADT) may affect cognitive function in men with prostate cancer (PCa). This study examined whether insomnia symptoms mediate the relationship between ADT and perceived cognitive function and whether depressive symptoms, fatigue severity, and physical activity moderate the strength of this relationship. Methods: This was a prospective study of ADT recipients (n = 83) who were matched with control patients with PCa who were not on ADT (n = 92) and with controls with no history of cancer (n = 112) over a 2-year follow-up period. Perceived cognitive function and satisfaction were assessed with the Everyday Cognition Scale. Insomnia was assessed with the Insomnia Severity Index. Multilevel mediation analyses were conducted to estimate the indirect effect of ADT on perceived cognitive function through insomnia symptoms. Exploratory moderated mediation analyses assessed whether the indirect effect of ADT on perceived cognitive function through insomnia symptoms was dependent on levels of fatigue, depression, or physical activity. Results: Insomnia symptoms significantly mediated the relationship between receipt of ADT and perceived cognitive function (P