Therapeutic effects of cerebrolysin added to risperidone in patients with schizophrenia dominated by negative symptoms

Objective: Cerebrolysin is a nootropic drug with unique neurotrophic activities directly affecting cerebral neurons. This study evaluated the efficacy and safety of cerebrolysin added to risperidone in patients with schizophrenia dominated by negative symptoms. Methods: The trial was a double-blind, placebo-controlled, parallel-group design. A total of 109 patients who met the DSM-IV diagnostic criteria for schizophrenia were randomly assigned to cerebrolysin (cerebrolysin plus risperidone, n=55) or placebo (risperidone only, n=54) groups. Intravenous infusions of 30 ml cerebrolysin or placebo were given once daily from Monday to Friday for 4 weeks. Efficacy was assessed with measurements including the Positive and Negative Symptoms Scale (PANSS), Wechsler Memory Scale (WMS), modified Chinese Wechsler Adult Intelligence Scale (mWAIS). and Clinical Global Impression (CGI). Results: Patients in both groups demonstrated improvements in psychiatric symptoms and cognitive and memory performance as assessed by PANSS, mWAIS, and WMS over the trial. There was no difference in rates of change in the PANSS total score or negative score between the two treatment groups. Patients treated with cerebrolysin showed significantly greater improvements in cognitive and memory function from week 2. No severe treatment adverse events were observed in either group. The frequency of adverse events was comparable between the two groups at the end of the treatment. Conclusion: Cerebrolysin added to risperidone did not augment the efficacy of risperidone in treating the psychotic symptoms of schizophrenia patients over an 8-week trial. Cerebrolysin at 30 ml per day as an adjunctive treatment was safe and may improve cognitive and memory functions of patients with schizophrenia dominated by negative symptoms.