Lifespan Trajectory of Affect in Cornelia de Lange Syndrome: Towards a Neurobiological Hypothesis

Background: Depressive symptomology and low affect are comparatively common in individuals with genetic disorders such as Cornelia de Lange syndrome. However, lifespan trajectories and associated person characteristics have not been examined. In this study, the trajectories for affect and associated behavioural characteristics were investigated in individuals with Cornelia de Lange syndrome with individuals with fragile X syndrome (FXS) comparable for chronological age and total number of behavioural indicators of ASD included for the purpose of contrast. Methods: A 7-year longitudinal study of affect (mood, interest and pleasure) was conducted in individuals with CdLS (n = 44) and FXS (n = 95). The trajectories of low affect were explored, as well as associations between Time 1 behavioural characteristics and affect at Time 1 and Time 3 (7 years later). Results: The CdLS group were lower in mood than the FXS group overall (p <.001). Interest and pleasure scores showed a significant decline over the lifespan for individuals with CdLS (p <.001) but not the FXS group. Lower level of ability at Time 1 was associated with lower mood at Time 1 and Time 3 in the FXS group only. Higher levels of ASD symptomology at Time 1 were associated with low mood and interest and pleasure in both syndrome groups at Time 1 and Time 3. Greater insistence on sameness at Time 1 was associated with lower mood at Time 1 in the FXS group and lower interest and pleasure at Time 1 and Time 3 in the CdLS group. Conclusions: Low affect in specific genetic syndromes may be associated with differing lifespan trajectories and behavioural profiles. Specifically, individuals with CdLS appear at risk for experiencing declines in levels of interest and pleasure whereas individuals with FXS show no significant change in the level of affect with age.