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Intellectual disability

You're most likely to come into contact with people with borderline or mild intellectual disability. Most people with such a disability are able to learn the many skills necessary to live in the community relatively independently.

What is intellectual disability?

As a worker in a drug and alcohol service, you're most likely to come into contact with people with borderline (IQ 70 to 80) or mild intellectual disability (IQ 55 to 70). About 85% of people who have an intellectual disability are classified as having a mild disability (IDRS 2011) and make up approximately 2% of the general population. Most people with borderline or mild intellectual disability are able to, with support, learn the many skills necessary to live in the community relatively independently (IDRS 2011).

People with moderate (IQ 40 to 55) and severe (IQ 25 to 40) levels of disability are less likely to present to drug and alcohol services due to their high support needs and their reliance on carers to support many daily functions.

The Diagnostic and Statistical Manual of Mental Disorders IV defines intellectual disability as consisting of three elements:

  • A person has an IQ below 70 (2 standard deviations below the mean)
  • A person displays at least 2 deficits in adaptive functions (such as communication, self-care, home living, social/interpersonal skills, self-direction, functional academic skills, health and safety), and
  • A person acquires the disability before 18 years of age.

These criteria are used by Ageing Disability and Home Care (ADHC) to determine NSW government disability service eligibility for people with intellectual disability. As such, people with borderline intellectual disability are not eligible for ADHC services, but they face many of the same disadvantages and struggles as those who are eligible for services and support.

The medical or diagnostic definition of intellectual disability focuses on the deficits of a person and does not take account of the level of support available to a person in their environment. A social perspective considers intellectual disability to reflect the interaction between the capabilities of a person and the structure of their environment.

In drug and alcohol services, adjusting a person's environment and support can increase their capacity to participate in treatment and reduce the effect of intellectual disability (IDRS 2009).

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"In drug and alcohol services, adjusting the environment and the supports for the person can increase their capacity to participate in treatment and reduce the effect of intellectual disability" (IDRS 2009).

What to consider when working with a person with an intellectual disability

Intellectual disability affects the way that a person learns. This includes:

  • The time taken to learn something
  • The ability to read and write
  • Communication and understanding
  • The ability to plan and solve problems
  • The ability to adapt to new and/or unfamiliar situations (IDRS 2009).

Stigma (negative social attitudes about people with intellectual disability)

Social stigma has a big impact on the lives of people with intellectual disability. Historically speaking, this has meant being socially shunned, segregated from the rest of society, and institutionalised. The reasons for these practices have focused on ideas of difference, deficits, and deviation from what is considered 'normal'. This has had extremely negative effects for people with intellectual disability.

While supports and services are moving away from former beliefs and practices like institutionalisation, and towards inclusive, human-rights-based approaches, the social stigma attached to intellectual disability is still acutely felt.

Little or none of the right kind of support

People with mild or borderline intellectual disability may not be eligible for the support they need, depending on their IQ and the scope of supports currently available. An absence of formal diagnosis, or no evidence that there has ever been diagnosis (e.g. evidence of having had a diagnosis would be available if a person had received services in the past from ADHC), are also barriers to specific support. This group is at high risk of falling through the gaps in service delivery. There is an increased risk of imprisonment due to the lack of access to support services, including access to drug and alcohol treatment services.

Other reasons for lack of support include:

  • Natural supportive relationships having broken down
  • Being unlikely or unable to form and maintain a range of positive supportive relationships without facilitation
  • Gravitating towards, or attracting, those who may influence, manipulate and take advantage of their vulnerability.

Avoiding support

There are people who may avoid services and support because they fear that past uncomfortable or shameful experiences will be repeated.These may include when the person has:

  • Not understood what's been said or written down
  • Had minimal say in shaping or controlling plans and support
  • Been unable to comply with service agreements and therefore exited from programs
  • Been belittled, bullied and/or abused by staff or other service users
  • Felt uncomfortable grouped with other people of similar disadvantage.

Emotional, social and health effects

Without suitable life options and individualised, flexible and adaptable supports that promote a feeling of some authority over their own lives, people are likely to experience:

  • Lack of self-determination
  • Poor self-esteem
  • Loneliness
  • Boredom
  • Anxiety and depression
  • Poverty.

These stressors can affect their mental and physical health. There are, for example, higher occurrences of mental and physical illness among people with intellectual disability than in the general population. People with intellectual disability, including borderline intellectual disability, are also overrepresented in the criminal justice system. In 2001, 18% of women and 27% of men in NSW prisons scored below the pass rate on an intellectual disability screening test (Butler & Milner 2003).

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What does this mean for drug and alcohol services?

Successfully supporting a person with an intellectual disability to complete treatment will often rely not only on the person's motivation but on the ongoing support offered by workers. Your expertise in being able to support clients to generalise the treatment program learnings to everyday life situations and address multiple life issues is key to improving and maintaining their health outcomes.The focus should be on engagement, individual strengths and self-determination.

Focus on strengths

A functional assessment of a person's strengths and limitations will allow you to develop a profile of the supports they need to complete the treatment program. If the appropriate supports are in place, their level of functioning, and therefore success in treatment, will generally improve.

Masking of disability

When you're working with a person with intellectual disability or a person who displays indicators of intellectual disability, don't make assumptions about their level of disability. Some people develop strategies to mask the effects of their disability, due to stigma and discrimination. For example, even if they appear to give all the right responses to your questions, it may not mean they understand what you've asked them.

To improve communication with people with intellectual disability:

  • Build rapport
  • Allow plenty of time - don't rush your interaction
  • Ask open questions, requiring more than a yes or no response
  • Deal with one piece of information at a time
  • Don't pretend you understand them if you don't.

"Successfully supporting a person with an intellectual disability to complete treatment will often rely not only on the person's motivation but on the ongoing support offered by workers."

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Find out more

For more information on functional assessment see Screening and Assessment for Cognitive Impairment.

For information on practical strategies when working with people with intellectual disability and people with other cognitive impairment conditions see Practice Tips for Workers.

IDRS (Intellectual Disability Rights Service) (2009) Introduction to Intellectual Disability, IDRS: Sydney.

NSW CID (Council on Intellectual Disability) (2006) What is Intellectual Disability? Factsheet, NSW CID: Sydney.

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