Transition from Obsession to Delusion in Schizo-obsessive Disorder: A Case Report and Literature Overview.

Schizo-obsessive disorder has been proposed to classify those who show schizophrenia and obsessive compulsive disorder (OCD) diagnoses. This subgroup has recently shown to be much more prevalent than previously thought, as well as presenting distinct clinical, phenomenological and neurobiological features from the parental diseases. We present a case report of a 32-year-old man who first manifested obsessive-compulsive symptoms (OCS) in his early twenties, followed by emergence of consistent negative schizophrenia symptoms, as well as intermittent aggressive behavior. After some years, there was a de novo manifestation of OCS followed by a transition of an obsession into delusion. Hence, we provide a brief and updated literature overview on the delusional transition of obsessions. For that, we searched the literature across the main academic databases for relevant articles on such a phenomenon until early 2017. This case report demonstrates a transition of a consistent obsession into an over-evaluated idea in a schizo-obsessive patient, associated with a decrease of the insight. There is evidence in the literature demonstrating that the transition of an obsessive symptom into a psychotic symptom, albeit rare, seems to be modulated by the presence and extent of insight and a sign of poor prognosis in the schizo-obsessive spectrum.