Comorbidity of obsessive-compulsive disorder and symptoms with nicotine dependence: Observational epidemiologic evidence from US-representative and psychiatric outpatient population-based samples.

Despite emerging evidence linking obsessive-compulsive disorder and symptoms (OCS) and nicotine dependence (ND), this comorbidity has received little research. To address this, the current investigation highlights evidence of this comorbidity in two epidemiologic datasets: (1) US nationally-representative survey (i.e., National Comorbidity Study-Replication; NCS-R), and (2) a psychiatric clinical epidemiology dataset (i.e., the Methods to Improve Diagnostic Assessment and Services; MIDAS). For NCS-R (n = 2088), interviews were carried as part of extensive data collection, including OCS symptom count and ND diagnosis. For MIDAS (n = 1257), as part of receiving mental health services at a US hospital outpatient treatment program, participants received diagnostic interviews, including evaluation of ND and obsessive-compulsive disorder (OCD), with OCS being characterized by self-reported symptom count. Results from NCS-R indicate that rates of current ND increased from 3.1% to 10.8% as OCS symptom count increased. Results from the MIDAS clinical sample exhibited a similar trend, but with higher overall figures compared to the US-representative NCS-R sample, with rates of current ND increasing from 18.3% to 41.4% as OCS count increased. In both datasets, OCS was positively associated with current (but not prior) ND after adjusting for psychiatric and sociodemographic covariates. For MIDAS, after adjusting for covariates, OCD diagnostic status was not associated with ND. Findings from this study lend support for the OCS-ND comorbidity in clinical and non-clinical populations and suggests that the OCS-ND link may be obscured when obsessive-compulsive phenomena is modeled as a dichotomous diagnostic variable versus as a dimensional construct.