Co-occurring conditions

Research theme leader: Professor Amanda Richdale

Researchers: Darren Hedley, Lauren Lawson, Katy Unwin, Simon Bury, Cheryl Dissanayake

Autistic people are at a high risk of co-occurring conditions, including mental and physical health difficulties. For example, this population experiences higher rates of anxiety, depression and insomnia than the general population.

These studies seek to understand the conditions that frequently accompany autism and support the needs of autistic individuals who are affected by them. In adults these conditions impact everyday functioning in the community and workplace. We aim to:

  • develop a better understanding of how these conditions affect the day to day lives of autistic people,
  • to better understand factors that may cause high rate of co-occurring conditions,
  • ensure that the tools we use to measure mental illness are accurate for autistic people (see our work on the HADS and PHQ-9 scales which measure anxiety and depression),
  • to develop supports that match the specific needs of the autistic community (e.g. the SLEAPI study), and
  • to educate government, frontline service providers and the general population about these co-occurring conditions and their impact on the lives of autistic people.

New research – Autism and Sleep

Jovevska, S., Richdale, A.L., Lawson, L.P., Arnold, S.R.C., & Trollor J.N. (2020). Sleep problems in autism from adolescence to old age. Autism in Adulthood. doi: 10.1089/aut.2019.0034

Difficulty sleeping is very common for autistic individuals. Our previous has examined sleep problems in autistic children, adolescents and adults as well as the role mental health and autism traits may have in poor sleep. Our most recent paper examined sleep from adolescence to old age in autistic and non-autistic people. Our latest study used data from SASLA and ALSAA (autistic Australians aged 15 to 80); we compared the sleep quality of autistic and non-autistic people.

We found that:

  • Poor sleep quality was more common for autistic individuals - 63.7% vs. 46.4%.
  • Autistic females and those aged 20 to 59 years were at a higher risk for poor sleep quality.
  • Having a mental health condition, medication and increased autistic traits increased risk for poor sleep quality.

Where to now? Our next steps are to start to better understand what causes poor sleep quality in autism so that we can develop effective sleep interventions for autistic adults.

Read more here

Media articles


Current studies


Suicide prevention and mental health & well-being in autistic adults

Funding: Suicide Prevention Australia

People with autism are at significant increased risk of dying by suicide compared to the general population. The study seeks to determine a) what factors are protective against suicide in autistic individuals and b) the underlying mechanisms by which these protective factors operate.Darren Hedley

Intervention for insomnia in autistic adults (ACT-i)

Funding: Latrobe University BHCRFA

This study is an adaptation (in consultation with autistic adults) of a brief, insomnia intervention utilising acceptance and commitment therapy (ACT) and behavioural therapy (BT) techniques to treat insomnia. Overall, there was an improvement in insomnia, anxiety and pre-sleep arousal following intervention.Amanda Richdale
Eric Morris
Lauren Lawson

SLEAPI: Intervention for insomnia in adults with autism spectrum disorder

Funding: La Trobe University

SLEAPI is based on the outcomes of ACT-i. It is a brief, novel, group-based insomnia intervention combining Acceptance and Commitment Therapy (ACT) and Behaviour Therapy (BT) to treat insomnia in autistic adults. The aim of this study is to implement and evaluate the efficacy of SLEAPI in comparison with sleep education to reduce insomnia symptoms and improve mental health and wellbeing.Amanda Richdale
Eric Morris
Lauren Lawson

Improving the competence of mental health practitioners in providing care to their autistic clients

Funding: School of Psychology and Public Health La Trobe University

To investigate the needs, barriers and enables of mental health practitioners optimising their practice for autistic adults and explore autistic adults' experience of mental health services and practitioners.R. Ball (PhD candidate)
Amanda Richdale
Eric Morris
Lauren Lawson

Substance use disorders in ASD: Associations with psychiatric and neurodevelopmental disorders

Funding: Fellowship to KU (2019-2020) - Future Leaders Waterloo & National Mental Health Research Institute Fellowship

We investigated the psychiatric and neurodevelopmental conditions associated with substance use disorders in autistic individuals as compared to a clinical control group.

Katy Unwin

From the National Mental Health Research Institute Cardiff University -
Jack Underwood
Jeremy Hall

Influence of autism symptoms and transdiagnostic factors on anxiety, depression and insomnia in adolescents with Autism Spectrum Disorder

Funding: Autism CRC and School of Psychology and Public Health La Trobe University

This study explored the relationships between insomnia, anxiety and depression among autistic adolescents and adults to identify relationships between autistic traits, sensory sensitivity, somatic arousal, intolerance of uncertainty, mental health and sleep. Path analysis showed that sensory sensitivities, intolerance of uncertainty and somatic arousal led to anxiety and then poor sleep and depression; anxiety, depression and sleep were inter-rated.

Alexa Jordan Chalmers (Masters candidate – Clinical Psychology)
Amanda Richdale
Lauren Lawson

Self-determination as a mediator between autistic traits and quality of life’

Funding: School of Psychology and Public Health La Trobe University

Autistic traits are associated with lower perceived quality of life. This study investigates whether Self-determination, the extent to which one believes they are a causal agent in their life, mediates this relationship.Helen Andrews (2020 honours candidate)
Simon Bury
Darren Hedley

Sex Differences in restricted and repetitive behaviours for adolescents and adults with Autism Spectrum Disorder

Funding: Autism CRC and School of Psychology and Public Health La Trobe University

This study investigated sex differences in self-reported restricted and repetitive behaviours (RRBs) and sensory behaviours, in autistic and non-autistic Australians (15-79 years). Autistic females had increased overall RRBs and sensory sensitivities than autistic males. This sex difference was not found in the non-autistic group.Samantha Lewis (2020 Honours candidate)
Lauren Lawson
Amanda Richdale

Examining Psychological Flexibility and other Transdiagnostic Psychological Processes in Poor Sleep

Funding: School of Psychology and Public Health La Trobe University

The study examined if psychological flexibility can explain poor sleep quality after accounting for autistic traits, intolerance of uncertainty, rumination and worry, and pre-sleep arousal. Intolerance of uncertainty, rumination and pre-sleep arousal were significant predictors of sleep quality.Michael Glas (2020 Honours candidate)
Eric Morris
Amanda Richdale

Psychological Inflexibility & Sleep: An Investigation of Contributing Inflexibility Processes and Mediating Factors

Funding: School of Psychology and Public Health La Trobe University

This study examined relationships between psychological flexibility, sleep, anxiety, and pre-sleep arousal. Path analysis showed that cognitive flexibility, present moment awareness, experiental avoidance and pre-sleep arousal accounted for significant variance in sleep quality.Lisa Purcell (2019 honours candidate)
Eric Morris
Amanda Richdale

An investigation of interoceptive ability in adults with and without Autism Spectrum Disorders

Funding: La Trobe University

This study examined the impact of autistic traits on interoception and whether a power posing intervention improved interoception. Only improvements in anxiety and social confidence were noted following the power posing intervention were found.Maddy Russell-Maynard (2019 honours candidate)
Tania Pietrzak
Amanda Richdale

Cognitive profiles associated with STEM occupations in ASD: Characterising the ‘autism advantage’

Funding: School of Psychology and Public Health, La Trobe University

This study explored cognitive skills associated with autistic traits using a multidimensional and multimodal approach to determine how mental health, physiological arousal and context interplay together and impact cognitive functioning. The findings will facilitate the ability to provide individualised cognitive remediation and tailored intervention strategies to support autistic adults.Eva Laurent (PhD candidate)
Amanda Richdale
Cheryl Dissanayake