I feel lonely a lot. I’ve got lots of things going on in my head all the time. I feel bad a lot of the time. I’m trying really hard at the moment to work it out. I don’t know if I’ll ever work it out - do you? I don’t think anything is getting better. (O’Connor & Fowkes, 2000)
People with intellectual disability are much more likely than other members of the population to experience depression, anxiety and other mental illness (Hayes, 2007). In Australia, the Australian Institute of Health and Welfare (AIHW, 2008) estimates that, in 2003, 57 percent of people with intellectual disability who were under 65 also experienced some form of psychiatric disability. Despite widespread knowledge of the prevalence of mental illness amongst people with intellectual disability, signs of mental illness, such as depression and anxiety, are often missed (UIDH, 2011).
People with intellectual disability may experience a reduced capacity to participate in standard clinical assessment processes, which can make diagnosis very difficult and result in limited access to appropriate mental health care (White et al., 2005). In the past, some practitioners considered that people with intellectual disability were not able to develop mental illness, due to their cognitive limitations; any unusual behaviour was considered a feature of their disability. Today, unusual behaviour for a particular person is considered a good indicator that they may be experiencing psychological distress (Hughes, 2009). If a person is displaying unusual behaviour that is causing them distress, it is important to have them assessed by relevant mental health professionals. Encouraging the person to speak to their GP may be an important first step.
Once a mental illness is recognised, clinicians may face challenges in determining the most appropriate treatment and carrying out the treatment. People with intellectual disability often require intensive support from psychiatrists, psychologists, family, friends and/or support staff. For example, the process of determining the most appropriate medication can be extraordinarily stressful for the individual and their family members, as it may lead to even more difficult behaviours and situations at home. Family or support workers may decide that this is too harmful for the person (or themselves) and not complete the process before the best medication has been identified. As part of the treatment process, clinicians may neglect to consider whether different treatment approaches may be appropriate for individuals with intellectual disability – including considering the broader issues that may be contributing to the situation, or questioning whether a holistic response to the wider issues in the person’s life could be beneficial (such as appropriate counselling or other non-pharmacological responses).
Hospitalisation for mental illness can be a traumatising experience for people with intellectual disability. The environment of hospital mental health units is frightening for anyone, and is particularly so for a person with intellectual disability. It may be difficult for doctors to identify what behaviours are normal for the person (and part of their disability) and what behaviours are due to a mental illness. It is essential that support workers and counsellors who know the person well advocate on their behalf to the clinicians who carry out the assessments and treatments. This will enable clinicians to get a clearer picture of what is and is not normal behaviour for this person.