[Clinical zoanthropy]

Abstract

Background: Clinical zoanthropy is a rare delusion in which a person believes himself or herself to be an animal.

Aim: To assess the clinical and scientific relevance of this classical diagnostic category.

Method: A search was conducted in the classical and scientific literature and in PubMed, Embase, and Ovid.

Results: Only 56 cases of clinical zoanthropy could be found in the international scientific literature. Since specific studies have yielded a relatively large numbers of cases in the past, it can be concluded that the disorder is probably more prevalent than is suggested in the literature. These cases may well be not only primary types, based on mental or unclear causes, but also secondary types, mediated by aberrant somatosensory sensations. Treatment of the underlying condition (in most cases a psychotic or mood disorder) has proved to be increasingly successful over time.

Conclusion: Because of the possible co-occurrence of zoanthropy and alterations in coenesthesis, i.e. the sensation of physical existence, mental health workers should be on the lookout for cases of clinical zoanthropy in clinical practice and avoid treating them in the same way as they would treat other delusions. All cases that occur should be subjected to extra somatic investigations – including an EEG and neuroimaging – and treatment should be adjusted in accordance with the findings.