In some clinical scenarios obsessive and delusive symptoms exhibit several similarities, making it challenging to differentiate between schizophrenia spectrum disorder (SSD) and obsessive-compulsive disorder (OCD). There are numerous reports of patients suffering from those disorders and manifesting both psychotic and obsession-like features, which makes accurate distinction even more complicated. We found several conflicting theories attempting to elucidate this overlap, one being the existence of the separate clinical entity - schizo-obsessive disorder.

The aim of this study is to consolidate current knowledge, synthesize existing theories and explore diagnostic implications.

We conducted a systematic literature review following the PRISMA protocol, we scrutinized studies addressing obsession-like symptoms in SSD, psychotic symptoms in OCD, and comorbidity of those disorders. We included peer-reviewed non-interventional studies published in English and Polish from 2013 onwards. The search was performed in the following medical databases: PubMed, Science Direct, Scopus, and Web of Science. Synthesis utilized a narrative approach due to diverse study designs, outcomes and observational nature of the collected data.

We identified several dozen articles, which revealed a range of diverse findings, often inconclusive, and occasionally conflicting, Although, the collected data indicate the schizo-obsessive spectrum exhibits clinical relevance.

The ambiguity in results emphasizes the necessity for further investigations into pathomechanism of schizophrenia and OCD. Future research, particularly involving children and adolescents, should strive for a comprehensive understanding of the nuanced manifestations of obsessive-like and psychotic symptoms in both disorders, aiding in refining diagnostic criteria and developing effective intervention strategies.

None Declared