The multifaceted question of whether psychiatric disorders are specific to human beings can not simply be answered "yes" or "no". Tackling the question can nevertheless be important because many symptoms characteristic of human psychiatric disorders can be found in behaviourally abnormal animals. From this perspective therefore the answer must be "no". Research into the environmental causes of such symptoms, for example in our closest extant relatives, the nonhuman primates, can potentially contribute to the prevention of human psychiatric disorders. Moreover, research into animal models of psychiatric disorders has made great progress in terms of both aetiology and (pharmaco-) therapeutic options. Even though the applicability of findings to human disorders is contested, it is hardly ever questioned. In any event, is there anything specific to humans that animal models can not express and that render studies of human experience and behaviour indispensible? The answer can only be "yes" because human experience and behaviour have evolved in a species-typical way. Accordingly, future multidisciplinary research should be thoroughly grounded in the natural sciences, preferably adopting a structure after Tinbergen's four "W" questions on ontogeny, mechanism, phylogeny, and adaptive value.