The antibiotic, minocycline possesses neuroprotective and anti-inflammatory factors. Several case studies, and small controlled trials have claimed that minocycline has had beneficial effects on negative symptoms in schizophrenia, such as apathy and social withdrawal. More recently, emerging evidence of inflammatory processes serving as underlying mechanisms in depression, and schizophrenia has strengthened interest in minocycline and other anti-inflammatory drugs as a new avenue for psychiatric treatment. In a recent double-blind, placebo-controlled, randomized controlled trial, patients with schizophrenia spectrum disorder with onset of symptoms within the past five years were recruited. Participants received minocycline (200mg/day for 2 weeks, then 300mg/day for the remainder of the 12-month study period). Primary clinical outcome was the negative score on the Positive and Negative Syndrome Scales (PANSS) across follow-ups at 2,6,9, and 12 months. The primary biomarker outcomes were medial prefrontal grey-matter volume, dorsolateral prefrontal cortex activation during a working memory task, and plasma concentration of interleukin 6. Compared with placebo, minocycline had no effect on ratings of negative symptoms (treatment effect difference -0.19,95% CI -1.23 to 0.85; p=0.73), the primary biomarkers outcomes did not alter over time, and were unaffected by the minocycline. The results suggest that there are no benefits to the application of minocycline in potentially treating negative symptoms related to schizophrenia. Prior to further research, a more specific inflammatory mechanism associated with the disease, would need to be developed.
Reference:
CDeakin et al. The Lancet. 2018; 5:885-894. Abstract
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