GAD
Of all the anxiety issues Generalised Anxiety Disorder (GAD) is considered to be the most prevalent, and some investigators have argued that GAD may be the most difficult of the anxiety disorders to treat. Generalised Anxiety Disorder was first introduced as a diagnosis in the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) (APA, 1980). Although there are other cognitive and somatic symptoms, it was not until the publication of DSM-III-R (APA, 1987) that GAD was uniquely defined by chronic and pervasive worry (Barlow, Blanchard, Vermilyea, Vermilyea & DiNardo, 1986), causing significant impairment across most of the domains of a persons life.
The diagnostic criteria for GAD In the Diagnostic and Statistical Manual of Mental Disorders has changed very little over the years. it was revised in the DSM-IV-TR and the only difference between this and the most recent manual the DSM-V is the change from 6 months of worry occurring to 3 months as one of the diagnostic conditions (APA 2013). It has been suggested that the classification should be re-labeled Generalised Worry Disorder
A reductionistic view of the DSM diagnostic criteria for GAD are, excessive anxiety and worry (apprehensive expectation), about a number of events or activities. The person finds it difficult to control the worry. The anxiety and worry are associated with restlessness or feeling keyed up or on edge, being easily fatigued, difficulty concentrating or mind going blank, irritability, muscle tension and sleep disturbance (difficulty falling or staying asleep, or restless unsatisfying sleep).
The prevalence of GAD is quite remarkable and it is considered to be the most reported of all the anxiety disorders. In a recent survey by the National Institute of Mental Health in America it showed that GAD affected about 6.8 million Americans 18 years and older in a given year. In a New Zealand survey published by the Mental Health Foundation of New Zealand 1997, it was suggested that Generalised Anxiety Disorder affects almost one-third of the adult population during their lifetime.
It seems that GAD can develop gradually, and begin at any point of our lives. Patients with GAD often present with a life-long history of generalized anxiety. Several studies have found that a large proportion of patients with GAD cannot report a clear age of onset or report an onset dating back to childhood (see, e.g., Anderson, Noyes, & Crowe, 1984; Barlow, Blanchard, Vermilyea, Vermilyea, & Di Nardo, 1986; Butler, Fennell, Robson, & Gelder, 1991; Cameron, Thyer, Nesse, & Curtis, 1986; Noyes, Clarkson, Crowe, Yates, & McChesney, 1987; Noyes et al., 1992; Rapee, 1985; Sanderson & Barlow, 1990).