The potential link between suicide and antidepressant treatments in children and adolescents has recently attracted considerable media attention. In an Opinion article in this issue, Licinio and Wong discuss the science behind this controversy and the sequence of events that led to the FDA issuing a directive to pharmaceutical companies to include a 'black box' warning on all antidepressant medications to highlight this potential risk. Promising targets for the treatment of other psychiatric and neurological conditions are considered in two review articles in this issue: Schoepp and colleagues highlight the potential of metabotropic glutamate receptors as drug targets for anxiety and stress disorders, and Leurs et al. focus on the histamine H3 receptor, which has attracted much interest as a target for disorders including schizophrenia, attention-deficit hyperactivity disorder and obesity, summarizing the development of compounds that are directed towards this receptor and their effects in preclinical models. The use of preclinical models for cancer is the subject of the second in our series of articles on model organisms: in an Opinion article, Kamb critically evaluates the reasons for the poor predictive value of many models for cancer and describes how best to optimize their effectiveness. Cancer is one therapeutic area in which liposome-based drugs have been successful, and Torchilin describes the potential for further exploitation of liposomes in the pharmaceutical industry, and the importance of understanding the limitations of these approaches. Finally, in this issue's 'Guide to Drug Discovery' article, Gregson and colleagues discuss the development of appropriate pricing strategies for new medicines, a particularly crucial task for companies given the present dearth of new drug introductions.