Mental disorder in adults with intellectual disability. 1: Prevalence of functional psychiatric illness among a community‐based population aged between 16 and 64 years

Abstract

The reported prevalence of psychiatric illness among adults with intellectual disability (ID) varies widely between  and %; however, many methodological problems exist. The aims of the present study were to establish the prevalence of functional psychiatric illness among adults with ID who live in the community, in order to compare the overall rate and types of psychiatric illness between the population with ID and the general population without ID, and to establish the risk factors associated with psychiatric illness in adults with ID. The study was done in two stages. In the first part, a trained psychiatrist interviewed  randomly selected adults with ID and their carers using the Mini Psychiatric Assessment Schedule for adults with Developmental Disability (Mini PAS-ADD) to screen for psychiatric caseness. Out of these  adults,  had sufficient communicative abilities that made the administration of Mini PAS-ADD Correspondence: Dr Shoumitro Deb, Division of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff CF XN, UK (e-mail: Deb@Cardiff.ac.uk). possible. A second trained psychiatrist interviewed  out of the  adults who were diagnosed as psychiatric cases according to the initial Mini PAS-ADD interview. This psychiatrist interviewed patients and their carers in line with the full PAS-ADD interview. The second psychiatrist was blind to the initial diagnoses made according to the Mini PAS-ADD questionnaire. A final psychiatric diagnosis was made according to International Classification of Diseases - th Revision (ICD-) criteria. Some .% (% confidence interval = .-.%) of the cohort had a psychiatric diagnosis according to ICD- criteria: .% had schizophrenia, .% depressive disorder, .% generalized anxiety disorder, .% phobic disorder and % delusional disorder. The overall rate of functional psychiatric illness (point prevalence) was similar to that found in the general population (%). However, the rates of schizophrenic illness and phobic disorder were significantly higher in the study cohort compared with those in the general population (.% and .%, respectively). Increasing age and the presence of physical disability were significantly associated with the occurrence of psychiatric illness. Out of the  remaining adults with severe ID, two (%) had a diagnosis of a psychiatric illness (one mania and one anxiety disorder) according to the

Can a computerised training paradigm assist people with intellectual disabilities to learn cognitive mediation skills? A randomised experiment

“…Prevalence rates of mental health problems among people with intellectual disabilities (IDs) vary widely depending on the diagnostic criteria and assessments used, with recent estimates suggesting that between thirteen and forty percent of people with IDs are affected (Cooper, Smiley, Morrison, Williamson, & Allan, 2007;Deb, Thomas, & Bright, 2001;Emerson & Hatton, 2007). The high prevalence rates, when compared to the general population, can be partly explained by the genetic vulnerability of people with IDs, and disadvantageous life events such as stigmatisation and isolation (Clarke, 2003;Cooper et al, 2007;Emerson & Hatton, 2007;Hulbert-Williams & Hastings, 2008;Reiss & Benson, 1984).…”

Anxiety disorders in people with learning disabilities

“…A study cohort comparing people with learning disabilities with the general population revealed significantly higher rates of phobic disorder in the former (Deb et al, 2001a). A literature review (Raghavan, 1997) revealed a similar if not higher prevalence of generalised anxiety disorder in people with learning disabilities.…”

“…They are a heterogeneous, psychosocially disadvantaged and vulnerable group with a relatively higher prevalence of mental disorders (Borthwick-Duffy, 1994). Despite difficulties in the diagnosis and classification of psychiatric illnesses in this population (Fryers, 1997) there is ample evidence that anxiety disorders do occur (McNally & Ascher, 1987) and they are reported to be at least as common as in the general population, if not more so (King et al, 1994;Deb et al, 2001a).…”

Family burden related to clinical and functional variables of people with intellectual disability with and without a mental disorder

“…The service gap is particularly great in those suffering ID and co-occurring mental disorders (ID -MD) (Cooper, Smiley, Morrison, Williamson, & Allan, 2007a). The point prevalence of associated psychiatric disorders in ID is about 40% (including behavior problems) (Bailey, 2007;Cooper et al, 2007a;Deb, Thomas, & Bright, 2001) and an annual incidence of 8% has been reported . Although people with ID can suffer from the whole spectrum of psychiatric disorders, some are notably more common than in the general population.…”

“…Among the most commonly associated diagnoses are nonaffective psychosis (Salvador-Carulla, Rodríguez-Blá zquez, Rodríguez, Pé rez-Marín, & Velasquez, 2000;Cooper et al, 2007b) and bipolar disorder (Cooper, Smiley, Morrison, Williamson, & Allan, 2007c). ID-MD is also frequently linked to problem behaviors, which have prevalence around 20% in this population (Deb et al, 2001;Holden & Gitlesen, 2004;Lowe et al, 2007). The concept of family burden was imported to the study of ID from the mental health field.…”