Psychiatry has proven to be among the least penetrable clinical disciplines for the development of satisfactory in vivo model systems for evaluating novel treatment approaches. However, mood and anxiety disorders remain poorly understood and inadequately treated. With the explosion in the use of genetically modified mice, enormous research efforts have been focused on developing mouse models of psychiatric disorders. The success of this approach is largely contingent on the usefulness of available behavioural models of depression- and anxiety-related behaviours in mice. Here, we assess the current status of research into developing appropriate tests for assessing such behaviours.