Current antipsychotics have only a limited effect on two core symptoms of schizophrenia, negative symptoms and cognitive deficits. Minocycline is a second-generation tetracycline which has a beneficial effect in various neurological disorders. Recent findings in animal models and human case-reports suggest its potential for the treatment of these symptoms of schizophrenia. The current study aims to examine the efficacy of minocycline as add-on treatment for alleviating negative and cognitive symptoms in early-phase schizophrenia. The study will utilize a longitudinal double blind, randomized, placebo-controlled design with patients followed for six-months. Early-phase schizophrenia patients were recruited and randomly allocated to a minocycline or placebo treatment (2:1 ratio; 200 mg/day). The primary outcome measures are the Scale for Assessment of Negative Symptoms (SANS) and assessments of executive functions.