Studies on epidemiology and co-morbidities of adult Attention Deficit Hyperactive disorder in (ADHD) in northwest area of Ireland

This thesis is an endeavour to examine epidemiology of Adult ADHD in people attending mental health services in northwest area of Ireland. In addition, it examined mental health comorbidities including personality disorders, functionality, and quality of life in adults newly diagnosed with ADHD in their adult life. Further the association of childhood symptoms as they measured with the retrospective scale Wender Utah Rating Scale (WURS) with specific mental health disorders in adulthood (including ADHD) was explored. Finally, a new scale was developed and psychometrically tested which allows for the clinician routinely to measure clinical outcomes from interventions at individual level as well as overall outcomes of the service. The major findings of those studies where that there is a considerable number of undiagnosed or misdiagnosed ADHD cases among people attending adult mental health services (prevalence 16.1%). A meta-analysis of four similar studies shows a pooled prevalence of 16.31%. Also, the number of comorbid mental disorders in people with ADHD was higher compared to those without ADHD, and those with ADHD had significantly higher rates of depression and recurrent depression compared to those without. In the same line regarding personality disorders (PDs) the majority of those with ADHD had at least one comorbid PD the most common being the Dependent PD, followed by Depressive PD. Additionally, in terms of functionality and quality of life, those diagnosed with ADHD had significantly poorer functionality and lower quality of life compared to those with similar symptomatology but without ADHD diagnosis. Moreover, it was found that there was an association between certain childhood behaviours classified by WURS and later diagnosis in adulthood with ADHD, personality disorders, and substance abuse. Finaly, the new ADHD Clinical Outcome Scale (ACOS) tested in a sample of 148 participants, and it was found with high internal consistency (83%), high Inter-rater reliability (87%), good concurrent validity with Weiss Functional Impairment Rating Scale, 48%, and Adult ADHD Quality of Life Questionnaire (57%) and it was sensitive to clinical changes.
The above results of the studies which included in this thesis, had a major impact on the design and development of a new adult ADHD service in national level, and influenced the guidelines proposed in the Model of Care from the National Clinical Programme for Adult ADHD. In addition, at the local level the place where this research was carried out was the first where an ADHD tertiary clinic developed under the auspices of the National Clinical Programme.