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World Autism Month: Comorbidities in Adult Autism
A quarter of the general population have problems with their mental health at some point in their life. IN autistic people, this number is much higher with nearly 80% of adults with autism experiencing mental health issues during their lives.
Autism may co-occur with a number of physical and mental health difficulties. The prevalence is much higher for a range of conditions.
Mental Health
Anxiety
Anxiety disorders were diagnosed in 20.1% of autistic adults compared with 8.7% of population without autism in one study (Nimmo-Smith et al, 2019). Other studies suggest even 50% prevalence of anxiety symptoms in a group with autism (Lugnegard et al, 2011). In this study, from the spectrum of anxiety disorders the most commonly reported comorbidities were: social anxiety disorder (22%), generalised anxiety disorder, GAD (22%), agoraphobia (15%), panic disorder (13%) and obsessive-compulsive disorder, OCD (7%).
Hollocks with colleagues in his metanalysis estimated lifetime prevalence in autistic adults: social phobia -20%, OCD – 7%, GAD – 4%, agoraphobia – 4% (Hollocks et al, 2018).
Depression
According to research nearly 70% of autistic people had experienced at least one episode of major depression (Lugnegard et al, 2011). The prevalence of depressive disorders among individuals with autism was reported in several studies, which ranged from 1.47% to 54% (Hossain et al, 2020). Lifetime prevalence in other study was estimated to be 10% (Hollocks et al, 2018).
Bipolar disorder
Study suggests that in an outpatient sample of adults with autism, 6% of the patients could have current diagnosis of bipolar illness (Joshi et al, 2013). However, the rates of lifetime bipolar disorder could be higher for autism (25% lifetime prevalence), compared to non-autistic adults (13% lifetime prevalence).
Schizophrenia
People with autism are 3 times more likely to develop schizophrenia. Lugo Marin with colleagues estimated pooled prevalence of psychotic illness among adults with autism, in their metanalysis, at 6.4% (Lugo-Marin et al, 2018). Other studies suggested significantly higher prevalence of schizophrenia in individuals with autism than in controls, and the prevalence of autism in individuals with schizophrenia ranged from 3.4 to 52% (Zheng et al, 2018).
Gender Dysphoria
In large dataset reviews transgender and gender-diverse individuals were 3.03 to 6.36 times more likely to be autistic than were cisgender individuals (Warrier et al, 2020). Other research, employing diagnostic criteria for autism, suggested a prevalence of 6–26% in transgender populations, higher than the general population, but no different from individuals attending psychiatry clinics (Thrower et al, 2020).
Eating disorders
The reviewed studies showed that, on average, 4.7% of patients with certain eating disorder diagnoses (anorexia nervosa -AN; bulimia-BN; binge eating disorder -BED) received diagnosis of autism. For comparison large National Epidemiologic Survey in US estimates prevalence of lifetime AN, BN, and BED were 0.80%, 0.28% and 0.85% respectively (Udo et al, 2018).
Other study suggested a prevalence of 7.9% of eating disorder symptoms among autistic outpatient individuals, with anorexia and binge eating disorder being the most frequent (Karjalainen et al, 2016).
Addiction problems
In a systematic review conducted by Arnevik and colleagues on patients with autism and substance use disorder it was reported that the prevalence rates ranged widely, from 0.7% to 36%, and most studies involved highly selected samples. Such inconsistencies limit the comparisons between studies and render it difficult to establish an overall rate for the co-occurrence of autism and substance use disorder. No systematic prevalence studies of non-biased samples have been published (Arnevik et al, 2016).
Attention deficit/hyperactivity disorder(AD/HD)
Research combining data from multiplesources and analysed using meta-regression reported a worldwide-pooled estimate of 5.29–7.2% in children (Thomas et al, 2016), 2.5% in adults (Simon et al, 2009) and between 2.8% in older adulthood (Michielsen et al, 2012) in population without autism.
However, study by Lugnegard found prevalence of ADHD among autistic population at 30% (Lugnegard et al 2011) and meta-analyse by Lai found overall pooled prevalence estimates of 28% (95% CI 25–32) (Lai et al, 2019).
Intellectual disability
Intellectual disability (ID) and autism are two neurodevelopmental conditions noted to have a high degree of overlap and co-occurrence. Historically, symptoms of ID were reported to co-occur in approximately 70% or more of those with autism; however, the rate of co-occurrence is now believed to be around 32% (Bilder et al, 2013; Jill et al, 2020). Additionally several genetic conditions would present with significantly higher rate of autistic features, e.g. tuberous sclerosis complex or Fregile-X.
Physical Health
Epilepsy
Prevalence of epilepsy in the general population is between 1 and 2%, whilst general estimates suggest a prevalence of ~25–30% in individuals with autism (Parmeggiani et al, 2010).
Sleep disturbance
Autism has been found to be associated with diverse sleep alterations (Baglioni et al, 2016). Specifically it was correlated with both sleep discontinuity and shorter duration of REM sleep. From previous meta-analyses, it was found that overall pooled prevalence estimates of 12% (95% CI 10-15) for sleep–wake disorders (Lai et al, 2019).
Gastrointestinal problems
Large population-based studies found that individuals with autism present more often with gastrointestinal problems (34.7%) than neurotypical individuals, where most complaints concerned, with statistical difference, constipation, diarrhoea and oesophageal reflux (Croen et al, 2015).
References
Arnevik, E. A. and Helverschou, S. B. (2016) ‘Autism spectrum disorder and co-occurring substance use disorder – A systematic review’, Substance Abuse: Research and Treatment, pp. 69–75. doi: 10.4137/SART.S39921.
Baglioni, C., Nanovska, S., Regen, W., Spiegelhalder, K., Feige, B., Nissen, C., Reynolds, C. F., & Riemann, D. (2016). Sleep and mental disorders: A meta-analysis of polysomnographic research. Psychological bulletin, 142(9), 969–990. https://doi.org/10.1037/bul0000053.
Bilder, D., Botts, E. L., Smith, K. R., Pimentel, R., … Coon, H. (2013) ‘Excess mortality and causes of death in autism spectrum disorders: A follow up of the 1980s Utah/UCLA autism epidemiologic study’, Journal of Autism and Developmental Disorders, 43(5), pp. 1196–1204. doi: 10.1007/s10803-012-1664-z.
Croen, L. A., Zerbo, O., Qian, Y., Massolo, M. L., … Kripke, C. (2015) ‘The health status of adults on the autism spectrum’, Autism, 19(7), pp. 814–823. doi: 10.1177/1362361315577517.
Fodstad J.C., Elias R. and Sarawgi S. (2020) ‘Intellectual Disability in Autism Spectrum Disorde’. In White S.W., Maddox B.B. and Mazefsky C.A. (Eds.), The Oxford Handbook of Autism and Co-Occuring Psychiatric Conditions. Oxford Library of Psychology. doi: 10.1093/oxfordhb/9780190910761.013.10.
Joshi, G., Wozniak, J., Petty, C., Martelon, M. K., … Biederman, J. (2013) ‘Psychiatric comorbidity and functioning in a clinically referred population of adults with autism spectrum disorders: A comparative study’, Journal of Autism and Developmental Disorders, 43(6), pp. 1314–1325. doi: 10.1007/s10803-012-1679-5.
Karjalainen, L., Gillberg, C., Råstam, M. and Wentz, E. (2016) ‘Eating disorders and eating pathology in young adult and adult patients with ESSENCE’, Comprehensive Psychiatry, 66, pp. 79–86. doi: 10.1016/j.comppsych.2015.12.009.
Lai, M.-C., Kassee, C., Besney, R., Bonato, S., … Ameis, S. H. (2019) ‘Prevalence of co-occurring mental health diagnoses in the autism population: a systematic review and meta-analysis’, The Lancet Psychiatry, 6(10), pp. 819–829. doi: https://doi.org/10.1016/S2215-0366(19)30289-5.
Lugnegård, T., Hallerbäck, M. U. and Gillberg, C. (2011) ‘Psychiatric comorbidity in young adults with a clinical diagnosis of Asperger syndrome’, Research in Developmental Disabilities, 32(5), pp. 1910–1917. doi: 10.1016/j.ridd.2011.03.025.
Lugo Marín, J., Montserrat, ·, Rodríguez-Franco, A., Chugani, V. M., … Canal Bedia, R. (2018) ‘Prevalence of Schizophrenia Spectrum Disorders in Average-IQ Adults with Autism Spectrum Disorders: A Meta-analysis’, Journal of Autism and Developmental Disorders, 48, pp. 239–250. doi: 10.1007/s10803-017-3328-5.
Hollocks, M. J., Lerh, J. W., Magiati, I., Meiser-Stedman, R. and Brugha, T. S. (2019) ‘Anxiety and depression in adults with autism spectrum disorder: A systematic review and meta-analysis’, Psychological Medicine, pp. 559–572. doi: 10.1017/S0033291718002283.
Hossain, M. M., Khan, N., Sultana, A., Ma, P., … Purohit, N. (2020) ‘Prevalence of comorbid psychiatric disorders among people with autism spectrum disorder: An umbrella review of systematic reviews and meta-analyses’, Psychiatry Research. Elsevier Ireland Ltd, p. 112922. doi: 10.1016/j.psychres.2020.112922.
Michielsen, M., Semeijn, E., Comijs, H. C., Van De Ven, P., … Kooij, J. J. S. (2021) ‘Prevalence of attention-deficit hyperactivity disorder in older adults in The Netherlands’, pp. 1998–1999. doi: 10.1192/bjp.bp.111.101196.
Nimmo-Smith, V., Heuvelman, H., Dalman, C., Lundberg, M., … Rai, D. (2020) ‘Anxiety Disorders in Adults with Autism Spectrum Disorder: A Population-Based Study’, Journal of Autism and Developmental Disorders, 50(1), pp. 308–318. doi: 10.1007/s10803-019-04234-3.
Parmeggiani, A., Barcia, G., Posar, A., Raimondi, E., … Scaduto, M. C. (2010) ‘Epilepsy and EEG paroxysmal abnormalities in autism spectrum disorders’, Brain and Development, 32(9), pp. 783–789. doi: 10.1016/j.braindev.2010.07.003.
Rydzewska, E., Dunn, K. and Cooper, S.-A. (2021) ‘Umbrella systematic review of systematic reviews and meta-analyses on comorbid physical conditions in people with autism spectrum disorder’, The British Journal of Psychiatry, 218(1), pp. 10–19. doi: 10.1192/bjp.2020.167.
Simon, V., Czobor, P., Bálint, S., Mészáros, Á, & Bitter, I. (2009). Prevalence and correlates of adult attention-deficit hyperactivity disorder: Meta-analysis. British Journal of Psychiatry, 194(3), 204-211. doi:10.1192/bjp.bp.107.048827.
Thrower, E., Bretherton, I., Pang, K. C., Zajac, J. D. and Cheung, A. S. (2020) ‘Prevalence of Autism Spectrum Disorder and Attention-Deficit Hyperactivity Disorder Amongst Individuals with Gender Dysphoria: A Systematic Review’, Journal of Autism and Developmental Disorders, 50(3), pp. 695–706. doi: 10.1007/s10803-019-04298-1.
Udo, T. and Grilo, C. M. (2018) ‘Prevalence and Correlates of DSM-5-Defined Eating Disorders in a Nationally Representative Sample of U.S. Adults’, Biological psychiatry. 2018/04/17, 84(5), pp. 345–354. doi: 10.1016/j.biopsych.2018.03.014.
Warrier, V., Greenberg, D. M., Weir, E., Buckingham, C., … Baron-Cohen, S. (2020) ‘Elevated rates of autism, other neurodevelopmental and psychiatric diagnoses, and autistic traits in transgender and gender-diverse individuals’, Nature Communications, 11(1). doi: 10.1038/s41467-020-17794-1.
Zheng, Z., Zheng, P., & Zou, X. (2018) ‘Association between schizophrenia and autism spectrum disorder: A systematic review and meta-analysis.’, Autism research : official journal of the International Society for Autism Research., 11(8), pp. 1110–1119. doi: 10.1002/aur.1977.
Resources
- Gillan Drew, An Adult with an Autism Diagnosis: A guide for the Newly Diagnosed. Jessica Kingsley Publishers.
- Jeanette Purkins, Emma Goodall, Jane Nugent, The Guide to Good Mental Health on the Autism Spectrum. Jessica Kingsley Publishers.
- Lee A. Wilkinson, Overcoming Anxiety and Depression on the Autism Spectrum : A Self-Help Guide Using CBT. Jessica Kingsley Publishers.
- Luke Beardon, Autism and Asperger Syndrome in Adults. Sheldon Press.
- Matt Tincani, Andy Bondy, Autism Spectrum Disorders in Adolescents and Adults: Evidence-based and promising Interventions. Guilford Press.
- Valerie Gaus, Living Well on the Spectrum: How to Use Your Strenghts to Meet the Challanges of Asperger Syndrome/High-Functioning Autism. Guilford Publications.