Modafinil is a central nervous system wake promoting agent used for the 
treatment of excessive daytime sleeping. Its vigilance promoting properties and 
low abuse potential has intrigued the scientific community and has led to use it 
as a cognitive enhancer, before its neural functions were understood. Here, we 
review the effects of modafinil in human cognition and emotion and its specific 
actions on symptoms in patients with schizophrenia and whether these are 
consistently effective throughout the literature. We also performed a systematic 
review on the effects of modafinil on neurotransmitter signalling in different 
areas of the brain in order to better understand the neuromechanisms of its 
cognitive and emotional enhancing properties. A review of its effects in 
schizophrenia suggests that modafinil facilitates cognitive functions, with 
pro-mnemonic effects and problem solving improvements. Emotional processing also 
appears to be enhanced by the drug, although to date there are only a limited 
number of studies. The systematic review on the neurochemical modulation of the 
modafinil suggests that its mnemonic enhancing properties might be the result of 
glutamatergic and dopaminergic increased neuronal activation in the hippocampus 
and in the prefrontal cortex respectively. Other neurotransmitters were also 
activated by modafinil in various limbic brain areas, suggesting that the drug 
acts on these brain regions to influence emotional responses. These reviews seek 
to delineate the neuronal mechanisms by which modafinil affects cognitive and 
emotional function. This article is part of a Special Issue entitled 'Cognitive 
Enhancers'.