The etiology and pathogenesis of schizophrenia remains unclear. Immune dysfunction hypothesis for schizophrenia has attracted increasing attention of the researchers, substantial evidences suggested the levels of C-reaction protein and cytokine such as IL-1β, IL-6, TNF-α markedly elevated in patients with schizophrenia which may be particularly relevant for the cognitive impairment and metabolic disturbance of schizophrenia. In recent years, it has been demonstrated the beneficial effects of berberine on regulating lipid and glucose metabolism, reducing the proinflammatory status and improving cognition. As the investigators known, the report of berberine being used in schizophrenia is rare. This protocol is aim to evaluate berberine, as an adjunctive therapy, on inflammatory markers, lipid and glucose metabolism, cognition in patients with schizophrenia.

Inclusion Criteria:

• Individuals who age 18 to 60 years diagnose schizophrenia according the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID).
• The patients have illness for less than 5 years and have stable dose of the current antipsychotic drug for at least one month.
• Well established compliance with inpatient treatment per treating clinician's judgment. On baseline, at least 60 for Positive and Negative Syndrome Scale (PANSS) total score.
• Able to complete the cognitive assessment battery Female subjects will be eligible to participate in the study if they are of non-childbearing potential or of child-bearing potential and willing to practice appropriate birth control methods during the study.

Exclusion Criteria:

• Individuals who refuse to provide informed consent.
• Currently substance abuse or psychiatrically unstable per treating clinician's judgment.
• One with significant medical illnesses including uncontrolled hypertension, diabetes, seizure disorder, severe cardiovascular, cerebrovascular, pulmonary, or thyroid diseases also not suitable for this trial.
• Currently on anti-inflammatory or immunosuppressant medication including oral steroids and history of chronic infection (including tuberculosis, HIV and hepatitis), malignancy, organ transplantation, blood dyscrasia, central nervous system demyelinating disorder, and any other known autoimmune or inflammatory condition pregnancy or breastfeeding.