Modafinil has shown a number of cognitive-enhancing effects in studies on animals and is currently being used in clinical trials. These include improvements in episodic memory, working memory, and attentional processes that require cognitive control. The cognitive effects of modafinil are mediated by the action of its dopamine (DA) agonist. DA is a neurotransmitter associate with vigilance, and a recent study found that a dose-dependent enhancement of DA-induced wakefulness was related to improved performance on spatial discrimination tasks in rats. Episodic Memory Several studies have shown that modafinil improves memory performance on cognitive tests in patients with narcolepsy. The effects…