Despite the growing body of evidence that supports the existence of a specific epidemiological, genetic, and neurobiological relationship between OCD and schizophrenia, the association remains poorly understood. Here, a brief overview.
■ "OCD with poor insight" in which "the individual thinks obsessive-compulsive disorder beliefs are probably true,"1(p237) should be considered a severe form of OCD and not be mistaken for a primary psychotic disorder. A careful history is required to ascertain for insight in previous OCD exacerbations
■ OCD with poor insight may respond to treatment with an SSRI without the addition of an adjunctive antipsychotic, or preferentially to adjunctive antipsychotic added to an SSRI. Because some individuals with OCD take longer to respond to SSRIs, a therapeutic trial of an SSRI at optimized dosages for at least 8 to 12 weeks should be tried before the addition of adjunctive antipsychotic medication
■ Primary OCD should be distinguished from de novo obsessive-compulsive sympoms (OCS) induced by atypical antipsychotics/serotonin-dopamine antagonists (SDAs); this highlights the importance of a careful history rather than mere cross-sectional examination
■ Persons with schizophrenia should be evaluated for OCS/OCD before starting or switching to an SDA and monitored prospectively for the emergence of de novo OCS
■ SDA-induced OCS may be dose-dependent; in managing treatment emergent OCS, whether to reduce the dosage of the atypical antipsychotic, switch to a different antipsychotic, or continue the atypical antipsychotic and treat the de novo OCS is a matter of clinical judgment. The decision should entail a risk/benefit analysis that considers the degree of antipsychotic response to the SGA and the severity of treatment emergent OCS, among other factors
■ As with pure OCD, OCD comorbid with schizophrenia may respond to treatment with an SSRI and/or adjunctive cognitive-behavioral therapy; first-line treatment for patients who meet criteria for both disorders consists of an antipsychotic and an SSRI
For more on this topic, please see "Comorbidity: Schizophrenia With Obsessive-Compulsive Disorder," by Alexandra Bottas, MD, from which this Tipsheet was adapted.
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Koran LM, Hanna GL, Hollander E, et al, for the American Psychiatric Association. Practice guideline for the treatment of patients with obsessive-compulsive disorder. Am J Psychiatry. 2007;164(Suppl 7):5-53.
Chiao-Li K, Cheng-Fang Y, Cheng-Chung C, et al. Obsessive-compulsive symptoms associated with clozapine and resperidone treatment: three case reports and review of the literature. Kaohsiung J Med Sci. 2004;20:295-301.
Singer J. The connection between OCD and psychosis. http://psychcentral.com/lib/the-connection-between-ocd-psychosis/00018989.
[Note: This Tipsheet was posted on July 9, 2013, and has since been updated.]
1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Arlington, Va: American Psychiatric Association; 2013.