The forbidden thoughts dimension and psychiatric comorbidities in a large sample of OCD patients: A possible link to bipolar I comorbid disorder

Abstract

ObjectiveMany theoretical models have been proposed to identify groups of patients affected by Obsessive Compulsive Disorder (OCD) and the most studied model categorized OCD into different classes according to symptom dimensions. The aims of this study were to evaluate the association between the lifetime presence of Forbidden Thoughts (FT) symptoms and lifetime psychiatric comorbidities and to examine socio-demographic and other clinical features related to the lifetime presence of FT in a large naturalistic sample. MethodsThe sample is composed of adult OCD patients from a tertiary center. The sample was divided into two subgroups according to the lifetime presence/absence of the FT. Differences between groups were analyzed with Student's t-test and χ2 tests. Subsequently we performed multivariate logistic regression. Results and conclusionsData regarding 601 subjects were collected. The 65.9% Experienced lifetime FT. Higher level of education, lower age at symptoms onset, abrupt onset type and bipolar I comorbid disorder were associated with the likelihood of having FT. Our findings confirm a high prevalence of the FT dimension and suggest that OCD with aggressive, sexual, religious obsessions could represent a specific endophenotype of this disorder. The specific relation between FT and comorbid bipolar disorder type I seems particularly interesting.