Modafinil, a novel cognitive enhancer, selectively improves neuropsychological 
task performance in healthy volunteers and adult patients with attention deficit 
hyperactivity disorder (ADHD). It has been argued that persistent cognitive 
deficits in patients with schizophrenia are responsible for the failure of many 
patients to rehabilitate socially even when psychotic symptoms are in remission. 
The present study examined the potential of modafinil as a cognitive enhancer in 
schizophrenia. Twenty chronic patients with a diagnosis of schizophrenia were 
entered into a double-blind, randomized, placebo-controlled crossover study 
using a 200 mg dose of modafinil. Modafinil had some cognitive enhancing 
properties in schizophrenia similar to those observed in healthy adults and 
adult patients with ADHD. Improvement was seen on short-term verbal memory span, 
with trends towards improved visual memory and spatial planning. This was 
accompanied by slowed response latency on the spatial planning task. No effect 
on stop-signal performance was seen. Importantly, significant improvement in 
attentional set shifting was seen, despite no effect of modafinil on this task 
being seen in healthy volunteers or ADHD patients. Modafinil may have potential 
as an important therapy for cognitive impairment in patients with schizophrenia, 
particularly because of its beneficial effects on attentional set shifting.