Anxiety and mood disorders

Abstract

Anxiety disorders as defined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5; American Psychiatric Association, 2013) "include disorders that share features of excessive fear and anxiety and related behavioral disturbance. Fear is the emotional response to real or perceived imminent threat, whereas anxiety is the anticipation of future threat." The fear or anxiety is not transient but persist, usually lasting six months or more. Within DSM-5 the chapter on anxiety disorders includes disorders that occur in childhood, namely separation anxiety disorders and selective mutism, but also specific phobias, social anxiety disorder (social phobia), panic disorder, agoraphobia, and generalized anxiety disorder. The focus of this chapter is to cover conditions that are commonly diagnosed in adult life and so come under sections F40 and F41 within the International Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10; World Health Organization, 1992), and include phobic anxiety disorders, panic disorders, and generalized anxiety disorder. Anxiety disorders do occur in people with ID but may be missed (Stavrakaki and Lunsky, 2007;Davis et al., 2008). Due to the limitations of DSM-5 and ICD-10 in diagnosing mental disorders in people with ID the Diagnostic Manual -Intellectual Disability (DM-ID; Fletcher et al., 2007) was developed in the USA and the Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation (DC-LD) was developed in the UK to compliment the ICD-10 (DC-LD; Royal College of Psychiatrists, 2001). The use of an adapted diagnostic system can increase the rates of diagnosing anxiety and other mental disorders in people with ID (Cooper et al., 2007).Anxiety disorders are estimated to occur in 2-17% people with ID (Reid et al, 2011), and it is generally accepted that rates of anxiety disorders are comparable to the wider population. The prevalence in the wider population for generalized anxiety disorder over a 12-month period is estimated to be 3.1%, and for agoraphobia 0.8% (Kessler et al., 2005), with a lifetime prevalence of 1.7% for agoraphobia in adolescents and adults (American Psychiatric Association, 2013). This compares to a point prevalence of 4% of anxiety disorders in a recent large-scale population study of people with ID in Glasgow, Scotland (Reid et al., 2011). Generalized anxiety disorder was the most common disorder at a rate of 1.7%, followed by agoraphobia at a prevalence of 0.7%. The participants in this study underwent a structured mental health assessment and the diagnosis was made Psychiatric and Behavioural Disorders in Intellectual and Developmental Disabilities, ed. Colin Hemmings and Nick Bouras.