Skip to main content Accessibility help
×
Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-05T02:32:11.766Z Has data issue: false hasContentIssue false

3 - Psychiatric illness and disorders of intellectual development: a dual diagnosis

from Part 2 - Disorders of intellectual development: comorbidity and complications

Published online by Cambridge University Press:  01 January 2018

Marc Woodbury-Smith
Affiliation:
Associate Professor and CIHR Clinician- Scientist, Departments of Psychiatry & Behavioural Neurosciences
Sheila Hollins
Affiliation:
Emeritus Professor of the Psychiatry of Disability, St George's, University of London, UK
Get access

Summary

The psychiatrist plays a pivotal role in multidisciplinary teams that provide support and services for adults with disorders of intellectual development (DID). More than simply a historical artefact, however, this undoubtedly reflects the significance of the behavioural, medical and neuropsychiatric ‘complications’ of DID in terms of their prevalence and complexity, as well as the dynamics of families and support systems. These points notwithstanding, the psychiatrist is only one member of the multidisciplinary team, and the complexity inherent in ‘dual diagnosis’, alongside the important contributions made by relational and environmental factors, demands a range of skills, as will become apparent during the course of this chapter.

The aim of this chapter is to provide an overview of the comorbidity of DID and additional psychiatric illness. The wider concept of ‘mental health problems’ includes the large category of ‘behaviours which are experienced as challenging’, which are the subject of Chapter 5, while the pharmacological treatment of psychiatric illness in this population is discussed by Deb in Chapter 7. Therefore, the present chapter will focus on epidemiology, aetiology, assessment and diagnosis, and will give some overriding principles to consider in designing a management plan.

Epidemiology of psychiatric disorder

Although estimates of the prevalence of psychiatric disorder among individuals with DID vary widely, as a general rule it seems to be higher than in the general population. The variation in prevalence figures reflects bias in ascertainment, the diagnostic methods used and the characteristics of the populations studied, including the sample size (Smiley, 2005). Moreover, the prevalence in institutionalised samples tends to be higher. The most robust studies in epidemiological terms are summarised in Table 3.1. Even within this small number of studies, different methodologies have been employed and the prevalence figures vary widely (e.g. as low as 10% in California in the 1990 study of Borthwick-Duffy & Eyman, and as high as 31.7% in the 2008 study by Morgan and colleagues in Perth, Australia). It should be pointed out that some studies have calculated point prevalence (the studies by Rutter et al, Lund and Cooper et al), while, by their very methodology, others must be considered estimates of lifetime prevalence (the study by Morgan et al and both US studies).

Type
Chapter
Information
Publisher: Royal College of Psychiatrists
Print publication year: 2015

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×