A Developmental and Symptom-level Approach to Comorbid Mental Health Disorders in Children
Abstract
This dissertation addresses current issues in the conceptualization and classification of childhood mental health issues (e.g., impact of sex/age on symptoms, comorbidity, limits of traditional models). In contrast to traditional models, the importance and value of utilizing individual symptoms as primary variables of interest is presented. This first study consisted of 9565 participants (M = 12.06, SD = 3.57, 58% males). Results for youth with no history of trauma indicated sex differences in symptom expression consistent with what has been previously shown in the literature; however, a complex presentation of attention-related symptoms was identified for females. Similar sex differences were found for participants with a history of trauma; however, there were varying patterns of symptom clustering between all participant groups. Trauma-related symptoms often clustered with symptoms of other disorders. Various symptoms (e.g., impulsivity, episodes of panic, sleep concerns) are discussed as potential bridge symptoms between diagnoses.
The second study aimed to address current issues in the diagnosis and understanding of mental health concerns in participants with intellectual disabilities (n = 863, M = 12.00, SD = 3.65, 73% male). Results indicated that participants with a history of trauma displayed higher rates of all symptom categories except attention-related symptoms. The trauma group also exhibited symptom clustering that was more diagnostically complex than those without a history of trauma. The role of various symptoms in comorbidity is discussed.
The third study explored sex differences in symptoms, comorbidity and bridge symptoms using longitudinal data (n = 2661, 55% males; age at initial assessment M = 11.81, SD = 3.46; age at discharge assessment M = 12.32, SD = 3.46). Results showed significant symptom change between initial and discharge assessments for both sexes in all symptom categories. Sex differences in symptom severity were identified at both assessment times. Females exhibited a greater number of diagnoses initially and males exhibited a greater number at discharge. Females also exhibited a greater number of individual symptoms that did not change significantly between assessments. Implications for diagnosis and effective intervention are discussed. In the final chapter, the utility of the symptom-level analyses and implications for psychology and clinical practice are discussed.