Pharmacological mood enhancement – the improvement of mood and related mental functions by means of pharmaceuticals – raises a number of philosophical, ethical, and social questions. These questions are partly in line with questions known from the broader debate on human enhancement and partly relate to the ways in which neuroscience and neurotechnologies are affecting our ideas about who we are and how we should understand ourselves. This contribution gives an overview of the mood-enhancement discussion as it has played out in the academic literature over the last 20 years.