Modafinil improves cognition and attentional set shifting in patients with chronic schizophrenia

Abstract

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.