A fine line between obsessive-compulsive disorder (OCD) and psychotic disorder: a case report

AI Summary

OCD with poor insight can mimic psychosis, producing intrusive quasi-delusional fears, compulsions and perceptual disturbances, complicating differential diagnosis.
Lack of antipsychotic response and substantial improvement with paroxetine indicated an OCD aetiology, altering treatment and prognosis.
Prolonged mislabelling as psychosis can perpetuate belief in psychosis and fuel obsessive fears, highlighting need for careful differential diagnosis to avoid unnecessary neuroleptics.

J Med Case Rep. 2026 Jul 24;20(1):429. doi: 10.1186/s13256-026-06404-1.

ABSTRACT

BACKGROUND: Differentiating obsessive-compulsive disorder (OCD) from psychotic disorders can be problematic, especially when OCD symptoms present with poor insight and psychotic-like intensity.

CASE PRESENTATION: This case report describes a 44-year-old white male, whose symptoms began in his late teens. Clinical documentation, however, began in 2009, when he was first hospitalized. Although he was initially diagnosed with psychosis, his intrusive quasi-delusional fears and compulsions, accompanied by experiences of being watched and abstract ideas about the “ego” with limited insight, led to diagnostic uncertainty. While antipsychotic treatment was ineffective, the initiation of paroxetine in 2011 resulted in substantial improvement, suggesting an OCD etiology. Despite later revision of his diagnosis (after more than 10 years following manifestation) toward an OCD spectrum disorder, the patient continued to believe he had psychosis and developed obsessive fears of becoming psychotic, likely influenced by prior clinical labeling.

CONCLUSION: This case underscores the importance of careful differential diagnosis in OCD with poor insight. Early recognition of OCD can significantly alter prognosis and treatment course, avoiding prolonged exposures to neuroleptics.

PMID:42498968 | DOI:10.1186/s13256-026-06404-1

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