The Relationships Between Obsessive-Compulsive Disorder and Psychosis: An Unresolved Issue

The aim of the present paper was to review and comment on available literature on the complex relationships between obsessive-compulsive disorder OCD and psychotic disorders, with a focus on diagnostic issues, as well as clinical and prognostic implications.

The databases of PubMed, Scopus, Embase, PsycINFO and Google Scholar were accessed in order to research and collect articles published in English language only, according to the PRISMA guidelines. Free text terms and MeSH headings were combined as it follows: " Obsessive-compulsive disorder" OR "Obsessive-Compulsive Symptoms" AND "Schizophrenic Disorders" OR "Schizophrenic Symptoms" AND "Antipsychotic Treatment" OR "Second-Generation Antipsychotics "SGAs".

The relationships between obsessive-compulsive disorder (OCD) and schizophrenia spectrum disorders, intended as diagnostic categories, as well as the overlap between obsessive-compulsive and psychotic symptoms, represent an interesting example of how "neurosis" and "psychosis" actually stand along a longitudinal and transversal continuum, much more frequently than it was supposed in the past. It also poses a challenge for clinicians, since treating some symptoms of one disorder may trigger or worsen the other one.

The question of the symptom overlapping between OCD and psychoses remains unresolved, if considered within the stringent categorization of the available diagnostic systems, but even all the attempts to explain the heterogeneity of the clinical pictures, according to other theoretical constructs, result inconclusive. The controversial role of antipsychotics, especially of SGAs in the treatment of these complex patients is another problem to be clarified in future and more focused studies.