Over the last 15 years, genetically modified mice have added important data to our
knowledge on psychiatric diseases including anxiety. This has produced many behavioural
publications, partially by non-behaviourists, in which differences between mutants and
normal wild-type animals were described. The popularity of these novel tools allowing the
study of new mechanisms also, however, led to observations that could not be confirmed.
This review attempts to summarize various factors that can lead to difficult and partially …