A review of modafinil and armodafinil as add-on therapy in antipsychotic-treated patients with schizophrenia

Abstract

Schizophrenia is characterized by reality distortion, psychomotor poverty and cognitive disturbances. These characteristics contribute to a lesser social functioning and lower quality of life in patients with schizophrenia. It has been suggested that modafinil and its isomer armodafinil as an add-on strategy to antipsychotic treatment in patients with schizophrenia may improve cognitive functioning, attenuate fatigue, inactiveness and other negative functions as well as weight gain. In this paper we review the literature relevant to the question of whether modafinil and armodafinil are beneficial as add-on therapy in antipsychotic-treated patients with schizophrenia. A total of 15 articles were included in this review; of the 15 articles, 10 were randomized controlled trials (RCTs). Evidence for the use of modafinil or armodafinil as add-on therapy to antipsychotic drugs to alleviate fatigue, sleepiness and inactivity is inconclusive. One cohort study and one out of two single-dose crossover RCTs in which modafinil addition was studied could demonstrate a positive effect. All five RCTs of modafinil (three RCTs) and armodafinil (two RCTs) addition with a longer study duration could not demonstrate a positive effect. With respect to cognitive disturbances, animal models of cognitive deficits show clear improvements with modafinil. In RCTs with a treatment duration of 4 weeks or more, however, no positive effect could be demonstrated on cognitive functioning with modafinil and armodafinil addition. Yet, four single-dose crossover RCTs of modafinil addition show significant positive effects on executive functioning, verbal memory span, visual memory, working memory, spatial planning, slowing in latency, impulse control and recognition of faces expressing sadness and sadness misattribution in the context of disgust recognition. The addition of modafinil or armodafinil to an antipsychotic regime, despite theoretical and preclinical considerations, has not been proved to enhance cognitive function, attenuate fatigue, enhance activity, improve negative symptoms and reduce weight in patients with schizophrenia.