The development and validation of the Generalised Anxiety Disorder Inventory.
Generalised anxiety disorder (GAD) is a chronic condition that has a
significant impact on the lives of its sufferers. Although the validity of the diagnosis
has been the subject of much controversy in psychiatric circles, the prevalence and
economic impact of this syndrome warrants further study. Such research has hitherto
been generally lacking.
In the interests of furthering research, and of providing a tool to evaluate new
progressions in the treatment of GAD, the present thesis embarks on the
development of a new scale. The Generalised Anxiety Disorder Inventory (GADI)
seeks to provide a simple self-completion measure of GAD, which can be used to
track the severity of the condition over time.
Four studies are reported which document the initial stages of the
development and validation of the GADI. Study One describes the derivation of a
22-item scale from an initial pool of possible items. Studies Two and Three
describes initial reliability and validity statistics in two non-psychiatric populations.
Study Four reports the same reliability and validity analyses in a psychiatric
It is concluded that the GADI performs satisfactorily in the analyses
performed in the course of this thesis. However, in order to realise the scale's full
potential a number of additional, longitudinal studies are required. The thesis
concludes with suggested methodologies for these, and the news of a planned multi-centre
collaboration for their implementation.