Abstract
Background. Autism as was first described as a psychiatric disorder of childhood by Leo Kanner (1943) and Hans Asperger (1944). What is now described as autism spectrum disorder (ASD), is a group of complex neurodevelopmental disorders, first observable in early childhood, but now known to continue into adulthood. ASD affects an individual’s cognitive abilities in the domains of social-communication and flexibility of thinking, resulting in impairments in the ability to recognise and respond to the emotions of others, make and maintain relationships and difficulties adapting their own behaviour to suit the context. Over the last decade, there has been increasing evidence that adults with ASD also have major difficulties with emotion regulation and are susceptible to additional comorbid psychiatric disorders.
Aims. The research contained in this thesis has two major aims: (1) To examine the types of co-morbid psychiatric conditions experienced by a sample of people with ASD, with and without the additional variable of intellectual disability and (2) to examine similarities and differences in treatment and support options for adults with ASD compared to those provided for adults with ASD and/or an intellectual disability. These aims were pursued through three research questions:
1. What is the range and rate of co-morbid psychiatric conditions experienced by a population of adults with Autism Spectrum Disorders, and what is the effect of the additional variable of intellectual disability on the range and rate of disorders?
2. What interventions or treatments are currently identified as best practice in the provision of treatment for comorbid psychiatric disorders experienced by adults with autism?
3. What can be learned from the lived experience of adults with ASD in their contact with psychiatric and disability support services which will inform future models of practice and service provision?
Method(s) / Procedures. A mixed methods approach was used. The best fit for the research questions was two structured reviews followed by a QUAN+qual study design with the quantitative research being completed first and the qualitative aspect being used primarily for Complimentarity purposes, with a secondary Triangulation function. Six studies were carried out:
1. A structured review of pharmacological treatment for psychiatric disorders.
2. A structured review of psychological therapies for adults with autism.
3. A study of the presence of comorbid psychiatric disorder amongst a population of adults with autism and comparison group of people with intellectual disabilities
4. An evaluation of the psychometric properties of the Autism Spectrum Disorder-Comorbidity-Adults assessment tool which was utilised in Study Three.
5. A study of the psychiatric and behavioural profiles of adults with ASD who had both intellectual disability and multiple additional comorbidities.
6. Face to face interviews with 10 adults with autism in regard to their views and experiences on the provision of support and treatment service to adults who have both autism and a comorbid psychiatric disorder.
Results. Comorbid psychiatric disorders were frequently present in adults with ASD and the type of additional disorder was moderated by the severity of intellectual disability and autism symptoms. Those with ASD (AS/HFA) and IQ>70 experienced anxiety and depression whilst those with ASD+ID had ADHD or behavioural disorder though also had higher rates of depression and anxiety than the general population. Individuals who have severe ASD symptoms combined with severe or profound ID had multiple psychiatric comorbidities and needed 24 hr intensive support services.
The prescription rates of psychotropic medications for adults with ASD were high, with over 50% of adults in the study being prescribed one or more psychotropic medications. Despite these high rates of psychotropic medication use, participants had high rates of symptoms of comorbid disorders, indicating current approaches to treatment are not optimal.
Access to psychological treatment services is limited New Zealand unless the individual with ASD has a very severe psychiatric disorder and meets criteria for access to community mental health services. Adults with AS/HFA experience poor outcomes in adult life: only one of 15 adults with AS/HFA had been able to maintain a long-term personal relationship and only one had permanent employment.
Conclusions / Implications. A focus on treatment and support is essential in order that the best possible outcomes can be achieved for adults with ASD. Autism is now the most frequently diagnosed developmental disorder in children and the number of adults with a diagnosis is rising rapidly. Adults with ASD have high rates of comorbid disorder. In order to successfully treat these disorders, investment in both service development and research is required urgently. There is a need for new pharmacological research to find effective treatments for comorbid psychiatric disorders in adults with ASD, particularly for the treatment of anxiety, mood disorders and ADHD. Psychological therapies, particularly cognitive behaviour therapy, for the treatment of anxiety, depression, and emotion regulation amongst adults with ASD have growing evidence of effectiveness. Access to this type of therapy is limited for adults within New Zealand and should be increased, along with further research on efficacy. In addition, the following improvements to current services and practices could be achieved through a multi-provider/clinician coalition:
1. The development of a medication management protocol for adults with ASD+ID, including standardised treatment effectiveness measures, with the aim of ensuring optimum outcome and reducing polypharmacy.
2. The development of a standardised comorbidity assessment protocol for adults with ASD presenting at mental health services.
3. Screening for ASD amongst adults presenting with symptoms of psychosis for the first time.
4. A demonstration project to identify best practices in residential services for adults with ASD+ID and comorbid psychiatric and behavioural disorders.