The authors present the Cotard's syndrome, a rare psychiatric condition, pointing out the latest results in terms of psychoneurology and classification of the phenomenon. The central feature of the syndrome is a nihilistic delusion, in which the patient denies his or her own existence and that of the external world.

We searched electronic scientific databases using the appropriate search terms; relevant articles were carefully reviewed. We also present three cases from our clinical practice.

After the overview of the latest biological and neuropsychological findings, the terminology, the nosology, the classification and the differential diagnostics are discussed. To sum up with useful information for the clinical practice, the possible treatment strategies, the course and the prognosis of the disease are also presented.

The reported cases together with the reviewed literature suggest that a dimensional system of classifying Cotard's syndrome is preferable. At the one end of the spectrum is the presence of the pure nihilistic delusions, appearing as a symptom of an underlying psychiatric or neurological condition. The full-blown, classical syndrome as a diagnostic category forms the other end of the spectrum. The presented theoretical and practical aspects give a lead on deeper understanding, easier recognition and more adequate therapy of the Cotard's syndrome.