RATIONAL: 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.
OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSION: 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.