From the advent of electroconvulsive therapy in the 1930s to the emergence of magnetic seizure therapy in the 2000s, the refinement of brain stimulation in psychiatry has been largely motivated by a desire to achieve clinical efficacy and eliminate cognitive adverse effects. As a result of these efforts, a clinically efficacious brain stimulation technique that does not negatively affect cognition could soon be available. In the course of developing a 'cognitively safe' brain stimulation technique, potential methods to enhance various aspects of cognition have also emerged. In this article, we discuss the past, present and future of brain stimulation in psychiatry, and its effects on cognition.