Obsessive-Compulsive Disorder Across the Developmental Trajectory: Clinical Correlates and Cognitive Processing of Threat

Abstract

Controlled scientific research into obsessive-compulsive disorder (OCD) in adulthood has considerably progressed over the past two decades; however, current research into childhood OCD is still in its infancy by comparison. As a result, current psychological conceptualisations of OCD during childhood, including approaches to treatment, are almost entirely based on adult models of the disorder. Previous research however, examining the clinical phenomenology of OCD has provided some evidence that OCD might be associated with different clinical correlates at different stages of development. In particular, there appears to be a bimodal distribution in terms of the age of onset of the disorder, a male predominance during childhood and adolescence compared to adulthood, stronger familial aggregation of OCD in early onset cases, and differences in the types of symptoms and the patterns of comorbidity across age groups. The first study aimed to assess the developmental continuity in clinical correlates of OCD across 3 distinct age groups, including; children (n = 40), adolescents (n = 44) and adults (n = 41). It was hypothesised that the sample of children would be predominantly male, and would have a higher familial aggregation of OCD and/or anxiety/depression in first-degree relatives. It was further hypothesised that there would be significant age-related differences in terms of specific symptoms, patterns of comorbidity, OCD severity, functional impairment, and level of insight and distress. The results of this study supported the developmental heterogeneity hypothesis, with significant differences occurring across age groups on a number of clinical features of OCD including age at onset, symptoms experienced, comorbidity, severity, insight and impairment. The recognition of developmental differences in clinical features of OCD will assist in the accurate assessment and diagnosis of the disorder, and will allow for refinement of current treatment strategies to ensure treatments effectively target features of the disorder as it presents at different developmental stages. While the cognitive theory of OCD is one of the most widely accepted accounts of the maintenance of the disorder in adults, no study to date has systematically evaluated this theory across children, adolescents and adults with the disorder. Until empirical investigation examines the applicability of this theory to children and adolescents, we know very little about the cognitive processes associated with OCD during childhood or adolescence. The second study investigated developmental differences in the cognitive processing of threat in a sample of children (n = 34), adolescents (n = 39) and adults (n = 38) with OCD. Using an idiographic assessment approach, as well as self-report questionnaires, this study evaluated cognitive appraisals of responsibility, probability, severity, thought-action fusion (TAF), thought-suppression, self-doubt and cognitive control. It was hypothesised that there would be age related differences in reported responsibility for harm, probability of harm, severity of harm, thought suppression, TAF, self-doubt and cognitive control. Results demonstrated that children with OCD reported experiencing fewer intrusive thoughts, which were less distressing and less uncontrollable than those experienced by adolescents and adults with OCD. Furthermore, responsibility attitudes, probability biases and thought suppression strategies were significantly higher in adolescents and adults with OCD, compared to children. Cognitive processes of TAF, perceived severity of harm, self-doubt and cognitive control were found to be comparable across age groups. These findings suggest that some cognitive biases associated with OCD in adults, are in fact also associated with OCD during childhood and adolescence, however there remains some discontinuity across specific cognitive processes. For a developmentally sensitive theory of OCD, further investigation is clearly warranted into other possible age related maintenance factors of this disorder. Implications of these 2 empirical investigations are highlighted and directions for future research are discussed.