A placebo-controlled study of the modafinil added to risperidone in chronic schizophrenia

In recent years, evidence suggests that modafinil may be useful for certain symptom domains of schizophrenia, especially for the negative and cognitive symptoms. However, the results are not consistent.

This study was designed to investigate the effect of modafinil added to risperidone in patients with chronic schizophrenia in a double blind and randomized clinical trial.

Participants were inpatients males (35) and females (11), ages 20-49 years at two teaching psychiatric hospital in Iran. All patients were in the active phase of the illness and met DSM-IV-TR criteria for schizophrenia. Patients were allocated in a random fashion 23 patients to risperidone 6 mg/day plus modafinil 200 mg/day and 23 patients to risperidone 6 mg/day plus placebo. The principal measure of outcome was the positive and negative syndrome scale (PANSS). Patients were assessed by a psychiatrist at baseline and after 2, 4, 6 and 8 weeks after the start of medication.

The modafinil group had significantly greater improvement in the negative symptoms as well as PANSS total scores over the 8-week trial. Therapy with 200 mg/day of modafinil was well tolerated and no clinically important side effects were observed.

The present study indicates modafinil as a potential adjunctive treatment strategy for treatment of schizophrenia particularly the negative symptoms. Nevertheless, results of larger-controlled trials are needed before recommendation for broad clinical application can be made.