A comparative study of obsessive-compulsive disorder in Costa Rica and the United States.

This study compares the presentation and expression of obsessive-compulsive symptoms between a Latin-American and North American sample. In Costa Rica (CR) and the United States (US), respectively, 26 and 52 affected individuals with early-onset obsessive-compulsive disorder (OCD) were recruited. The Yale Brown Obsessive Compulsive Scale (YBOCS), a semi-structured psychiatric interview, and self-report questionnaires were administered. Age of onset and the distribution of OCD across men and women were similar across groups. Both CR and US participants reported obsessions and compulsions, with similar frequencies of symptoms, and contamination, symmetry, and hoarding as the most common symptom subtypes. The US sample had higher YBOCS total severity scores than the Costa Rican group. Similarly, there were significant ethnicity effects for YBOCS compulsion [F(1, 70)=17.88, P<.001] and obsession severity [F(1, 70)=8.78, P<.001], with Caucasians having higher scores than Costa Ricans on both subscales. Comorbidity rates were higher for US Caucasians than Costa Ricans for all disorders; differences were significant for mood disorders [64.7% versus 34.6%], alcohol use [21.3% versus 3.8%], cannabis use disorders [19.1% versus 0%], and other substance use disorders [39.4% versus 0%]. Regression analyses revealed that ethnicity, trait anxiety, and proband status were the only significant predictors of total YBOCS severity. Findings suggest that the core phenotype of OCD is the same in both CR and the US, and perhaps biologically driven. However some features of OCD, such as impairment, may be culturally influenced, leading to differences in prevalence rates and treatment utilization.