Although obsessive-compulsive disorder (OCD) affects only about 2.5-3 percent of the population, individuals with subclinical obsessive-compulsive symptomatology experience increased levels of distress and comorbidity than those with a lesser degree or absence of such symptoms. Additionally, it is hypothesized that people with subclinical OCD are at increased risk for developing OCD than those without subclinical symptomatology. However, there has been very little research on the transition from subclinical to clinical OCD. Thus the goals for this research program are two-fold: 1) The first aim of this study is to investigate whether a one-day long cognitive behavioral intervention is effective for reducing long-term distress and severity related to both obsessive-compulsive and comorbid psychopathology symptomatology, as compared to a no-treatment control group. 2) Although there is very little data on incidence of new cases of OCD from a subclinical population, the second purpose of this study is to see if the intervention is effective in offsetting new cases of OCD, as compared to the control group. Both the treatment and control groups will be followed for a year; data from the control group will contribute to the scant body of literature on one-year OCD incidence from a subclinical population.