Examining the potential preventative effects of minocycline prescribed for acne on the incidence of severe mental illnesses: A historical cohort study

Background: Animal studies suggest that the antibiotic and microglial activation inhibitor, minocycline, is likely to have a protective effect against the emergence of psychosis but evidence from human studies is lacking. The aim of this study is to examine the effects of exposure to minocycline during adolescence on the later incidence of severe mental illness (SMI). Methods: A historical cohort study using electronic primary care data was conducted to assess the association between exposure to minocycline during adolescence and incidence of SMI. The Incidence Rate Ratio (IRR) was measured using Poisson regression adjusted for age, gender, time of exposure, socioeconomic deprivation status, calendar year and co-medications. Results: Early minocycline prescription ( n=13,248) did not affect the incidence of SMI compared with non-prescription of minocycline ( n=14,393), regardless of gender or whether or not the data were filtered according to a minimum exposure period (minimum period: IRR 0.96; 95% CI 0.68–1.36; p=0.821; no minimum period: IRR 1.08; 95% CI 0.83–1.42; p=0.566). Conclusions: Exposure to minocycline for acne treatment during adolescence appears to have no effect on the incidence of SMI.