Cigarette smoking in obsessive-compulsive disorder and unaffected parents of OCD patients.

BACKGROUND Cigarette smoking is more prevalent among individuals with psychiatric disorders than the general population. Obsessive-compulsive disorder (OCD) may be an intriguing exception, although no recent study has investigated this hypothesis in OCD patients. Moreover, it is unknown whether reduced smoking rates are present in unaffected first-degree relatives of OCD patients. METHODS We assessed smoking prevalence in adults with OCD and unaffected parents of youth with OCD (PYOCD). To this end, 113 adults with OCD completed online questionnaires assessing symptom severity and smoking status. Smoking status was obtained from an independent sample of 210 PYOCD assessed for psychiatric diagnoses. RESULTS Smoking prevalence rates in adults with OCD (13.3%; n=15) and PYOCD (9.5%; n=20) samples were significantly lower than those found in representative samples of the general population (19-24%, all P<.001) and Axis I disorders (36-64%; all P<.001). There were no smokers in the adult OCD subset without clinically significant depressive symptoms (n=54). CONCLUSION Low prevalence of smoking in OCD may be familial and unique among psychiatric disorders, and might represent a possible state-independent OCD marker. Hypotheses concerning the uncharacteristically low prevalence rates are discussed with relation to OCD phenomenology and pathophysiology.