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S32 Step By Step Guide

Diagnosis and Classification

Most people with intellectual disability are born with their disability. For other people, the disability may result from illness or an injury during their developmental years. It is not uncommon for a person's intellectual disability to go undiagnosed during childhood. For some, the disability is first diagnosed in prison.

You cannot tell that a person has an intellectual disablity from how they look. It is through interacting with your client that you may begin to suspect there is a difficulty. Many people with intellectual disability will deny any difficulty and may work hard to cover up the effects of their disability in their everyday life.

Classification of intellectual disability

The terms mild, moderate, severe and profound may be used to describe the severity of a person's intellectual disability. These terms simply refer to the range of IQ within which your client has been assessed. They have limited usefulness but are included because they continue to be used and it is important to understand what they mean. Note that 'average' IQ is around 100.

Borderline intellectual functioning

'Borderline intellectual functioning' is defined in the DSM-IV-TR as describing 'an IQ range that is higher than that for mental retardation' (generally IQ 71-84). An assessment of borderline intellectual functioning may bring a client within the ambit of section 32 if there are concurrent deficits in areas of adaptive functioning.

Clinical term IQ
Borderline intellectual functioning 71 up to 84
Mild 50-55 up to around 70
Moderate 35-45 up to around 50-55
Sever 20-25 up to around 35-40
Profound Below 20-25

Categories are derived from the American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text Revision 2000 (DSM-IV-TRDiagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision 2000)

Common misconceptions about 'mild' intellectual disability

85% of people who have intellectual disability are within the mild category. The term 'mild' can suggest the disability is somehow insignificant or minimal in its effects. This notion is simply wrong. You should be alert to this possible misinterpretation by a magistrate or prosecutor. Mild intellectual disability has major effects.

People assessed to have mild intellectual disability fall within the bottom 2 per cent of the population in intellectual functioning. Without support or specific training they are likely to have significant difficulty with:

  • everyday survival skills
  • problem solving
  • planning
  • reading and comprehension of reading

An assessment by a psychologist will identify in detail specific strengths and weaknesses in your client's cognitive ability. It will also identify how the disability is affecting the client's everyday functioning. This detail is important to understand the effects of intellectual disability on the person and any links between the effects of the disability andthe alleged offending behaviour.

What is intellectual disability?Common Effects of Intellectual Disability

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