Effects of functional impairment on internalizing symptom trajectories in adolescence: A longitudinal, growth curve modelling study

Despite the fact that psychosocial and functional impairment has long been acknowledged as an important aspect of psychiatric diagnosis and treatment, relatively little is known about the longitudinal relationship between psychiatric symptoms and functional impairment. This is particularly true in childhood and adolescence. Understanding how symptoms relate to functional impairment is of great importance to clinicians and researchers as it is essential to nosology, treatment, and prognosis. This study sought to understand the developmental relationship between internalizing symptoms, functional impairment and gender in a sample of youth aged 10–15 using growth curve methods. Key findings indicate that the presence of functional impairment was associated with increased baseline internalizing symptoms scores but had no effect on the slope of internalizing symptoms trajectories during adolescence. The study highlights that the association between internalizing symptoms and functional impairment appears to be constant, linear and does not vary by gender.

► Functional impairment was associated with increased baseline internalizing symptom scores.
► Functional impairment had no effect on the slope of internalizing symptom trajectories.
► Female internalizing symptom trajectories inclined from age 10 to 15.
► Male internalizing symptom trajectories declined from age 10 to 15.
► The association between internalizing symptoms and functional impairment is constant, linear and does not vary by gender.