The long-term association of OCD and depression and its moderators: A four-year follow up study in a large clinical sample.

BACKGROUND: Depression is the most common comorbidity in obsessive-compulsive disorder (OCD). However, the mechanisms of depressive comorbidity in OCD are poorly understood. We assessed the directionality and moderators of the OCD-depression association over time in a large, prospective clinical sample of OCD patients. METHODS: Data were drawn from 382 OCD patients participating at the Netherlands Obsessive-Compulsive Disorder Association (NOCDA) study. Cross-lagged, structural equation modeling analyses were used to assess the temporal association between OCD and depressive symptoms. Assessments were conducted at baseline, two-year and four-year follow up. Cognitive and interpersonal moderators of the prospective association between OCD and depressive symptoms were tested. RESULTS: Cross-lagged analyses demonstrated that OCD predicts depressive symptoms at two-year follow up and not vice a versa. This relationship disappeared at four-year follow up. Secure attachment style moderated the prospective association between OCD and depression. CONCLUSIONS: Depressive comorbidity in OCD might constitute a functional consequence of the incapacitating OCD symptoms. Both OCD and depression symptoms demonstrated strong stability effects between two-year and four-year follow up, which may explain the lack of association between them in that period. Among OCD patients, secure attachment represents a buffer against future depressive symptoms.

Age of onset in obsessive-compulsive disorder: admixture analysis with a large sample.

BACKGROUND: Research into age of onset in obsessive-compulsive disorder (OCD) has indicated significant differences between patients with early and late onset of the disorder. However, multiple criteria have been used arbitrarily for differentiating between early- and late-onset OCD, rendering inconsistent results that are difficult to interpret. METHOD: In the current study, admixture analysis was conducted in a sample of 377 OC patients to determine the number of underlying populations of age of onset and associated demographic and clinical characteristics. Various measures of anxiety, depression, co-morbidity, autism, OCD, tics and attention deficit hyperactivity disorder (ADHD) symptoms were administered. RESULTS: A bimodal age of onset was established and the best-fitting cut-off score between early and late age of onset was 20 years (early age of onset ≤19 years). Patients with early age of onset were more likely to be single. Early age of onset patients demonstrated higher levels of OCD severity and increased symptoms on all OCD dimensions along with increased ADHD symptoms and higher rates of bipolar disorder. CONCLUSIONS: It is suggested that 20 years is the recommended cut-off age for the determination of early versus late age of onset in OCD. Early age of onset is associated with a generally graver OCD clinical picture and increased ADHD symptoms and bipolar disorder rates, which may be related to greater functional implications of the disorder. We propose that age of onset could be an important marker for the subtyping of OCD.