An international team of researchers has discovered that doxycycline — an antibiotic widely used for acne and skin infections — may have a protective effect against the development of schizophrenia. The study was published in the American Journal of Psychiatry.

The scientists analyzed data from more than 56,000 Finnish adolescents aged 13–18. Those who took doxycycline had a one-third lower risk of developing schizophrenia by age 30 (1.4%) compared with patients who were prescribed other antibiotics (2.1%).

According to Professor Ian Keller of the University of Edinburgh, who led the study, the protective effect may be linked to doxycycline’s ability to penetrate the brain and suppress excessive synaptic “pruning” — a process believed to play a key role in the development of schizophrenia.

The effect was observed even at low doses of the drug and among adolescents with severe psychiatric disorders. At the same time, the reduced risk applied only to schizophrenia and did not affect other mental disorders.