Anxiety during the long-term course of obsessive-compulsive disorder

Objective: The study aimed to investigate anxiety and its relation with obsessive-compulsive symptoms during the long-term course of obsessive-compulsive disorder (OCD). Methods: We used data from the Netherlands OCD Association (NOCDA) study, which included 419 participants with OCD (aged 18-79 years). Severity of obsessive-compulsive symptoms and anxiety at baseline and after two, four, and six years were entered into three models, which were analyzed using structural equation modeling: 1) the cross-lagged model, which assumes that anxiety and obsessive-compulsive symptoms are two distinct groups of symptoms interacting directly on the long-term; 2) the stable traits model, which assumes that anxiety and obsessive-compulsive symptoms result from two distinct latent factors, which are stable over the time and interact with each other; and 3) the common factor model, which assumes that anxiety and obsessive-compulsive symptoms are presentations of the same latent factor. Results: The cross-lagged model and the stable traits model both were valid models with a good model fit. The common factor model had a poor model fit and was rejected. Limitations: The duration of OCD varied widely between the participants (0-64 years). The majority experienced obsessive-compulsive symptoms since several years, which may have affected results on the course of anxiety and the interaction between anxiety and obsessive-compulsive symptoms. Conclusions: Anxiety and obsessive-compulsive symptoms in OCD patients do not result from a shared underlying factor but are distinct, interacting symptom groups, probably interacting by distinct latent factors.