Can People With Autism Also Have Another Mental Health Disorder?

Summary: Yes, people with autism can have another mental health disorder, and frequently receive a dual diagnosis, sometimes called a comorbid diagnosis or a diagnosis for co-occurring disorders.

Key Points:

• It’s common for a person with autism to receive a diagnosis for another mental health disorder.
• Features of autism – formally called autism spectrum disorder or autism spectrum disorders and shortened to ASD – can overlap with other mental health disorders.
• Symptom overlap and similarity can create challenges in diagnosis and treatment for people with autism spectrum disorders and another mental health disorder.
• Despite the challenges, recent advances in awareness of neurodivergence means people with autism and another mental health disorder can receive effective professional support.

Autism and Another Mental Health Disorder: What’s Terms Do We Use?

When people have more than one diagnosis, whether mental health, physical health, or behavioral health, there are a number of terms clinicians use to describe the phenomenon. These terms include dual diagnosis, comorbidity, co-morbid disorders, or co-occurring disorders. For the general public and most people who don’t specialize in a health-related field or occupation, these terms all mean the same thing.

However, officially speaking, comorbid and/or dual diagnosis means when people have a clinical diagnosis for two or more physical or mental health disorders at the same time, while having co-occurring disorders means when people have clinical diagnosis for a mental health disorder and a substance use disorder (SUD), a.k.a. addiction, at the same time.

In this article, we’ll use these terms interchangeably, and default toward dual diagnosis or co-occurring disorders rather than comorbid disorders or comorbidity, because dual diagnosis and co-occurring are more readily understood by people new to reading articles on mental health, neurodiversity, and/or addiction, whereas comorbid often requires explaining that morbid doesn’t necessarily imply worse or mean something is negative or bad.

With all of that said – and hopefully understood – we’ll use the rest of this article to discuss the prevalence of co-occurring mental health disorders among people with a primary diagnosis of autism and/or autism spectrum disorders (ASD).

Prevalence of Co-Occurring Autism and Mental Health Disorders

In the publication “Prevalence of Comorbid Psychiatric Disorders Among People With Autism Spectrum Disorder: An Umbrella Review of Systematic Reviews and Meta-Analyses,” published in 2020, and the publication “Prevalence of Co-Occurring Conditions in Children and Adults With Autism Spectrum Disorder: A Systematic Review And Meta-Analysis,” published in 2023, two groups of researchers examined all the data on the prevalence of co-occurring autism and mental health disorders available in reputable peer-reviewed scientific and medical journals.

The authors of the most recent study offer this rationale for conducting their extensive review and meta-analysis:

“The knowledge of the prevalence of co-occurrence in autism is fundamental to set up health services, especially mental health services, for adequate screening, diagnosis, and management of these conditions in people with autism.”

The authors also cite specific need for understanding of the prevalence among children:

“Early detection and accurate comorbidity diagnosis are crucial to address the clinical and socio-educational needs of these children.”

We couldn’t agree more: as mental heath professionals, we can’t treat people without a diagnosis, and in order to move toward accurate, timely diagnoses, we need facts about what’s happening with people now – or as close to now as possible – in the real world.

To that end, we’ll present the results of these two large-scale reviews below. First, however, we’ll report that in the first study – the one published in 2020 – researchers reported the prevalence of any co-occurring mental health disorder among people with autism, whereas the second study – the one published in 2023 – reported prevalence by specific disorder only. The results of the 2020 study showed for any co-occurring disorder among people with autism, the prevalence was 54.8 percent.

Now let’s look at the data from both studies, selected for relevance to the topic of this article.

Autism and Mental Health Disorders: Prevalence in 2020 and 2023

Attention-deficit hyperactivity disorder (ADHD):

• 2020 (total): 28%
  • Ages 18+: 25.7%
  • Ages 6-17: (detailed data n/a)
• 2023: 37%
  • Ages 18+: 22%
  • Ages 6-17: 45%

Anxiety disorders:

• 2020: 27.8%
  • Ages 18+: 42%
  • Ages 6-17: 39.6%
• 2023: 35%
  • Ages 18+: 28%
  • Ages 6-17: 42%

Sleep–wake disorders:

• 2020: 13%
  • (detailed age data n/a)
• 2023: 25%
  • Ages 18+: 21%
  • Ages 6-17: 30%

Depressive disorders:

• 2020: 24.8%
  • (detailed age data n/a)
• 2023: 18%
  • Ages 18+: 34%
  • Ages 6-17: 19%

Disruptive, impulse-control, and conduct disorders:

• 2020: 12%
  • (detailed age data n/a)
• 2023: 17%
  • Ages 18+: 7%
  • Ages 6-17: 20%

Obsessive-compulsive disorder:

• 2020: 17.4%
  • (detailed age data n/a)
• 2023: 9%
  • Ages 18+: 10%
  • Ages 6-17: 10%

Bipolar disorders:

• 2020: 13.5%
  • (detailed age data n/a)
• 2023: 7%
  • Ages 18+: 9%
  • Ages 6-17: 7%

Schizophrenia spectrum disorders:

• 2020: 11.8%
  • (detailed age data n/a)
• 2023: 10%
  • Ages 18+: 10%
  • Ages 6-17: 10%

We’ll discuss these results below.

Autism and Co-Occurring Disorders: Inside the Numbers

In order from greatest to least prevalence of co-occurrence, the most recent results – those from 2023 – show the following prevalences.

First, the data for adults.

For Adults: Autism and Mental Health Disorders

1. Depressive disorders: 34%

• • • Non-ASD: 7.4%

128% difference

2. Anxiety disorders: 28%

• • • Non-ASD: 21%

30% difference

3. Attention-deficit hyperactivity disorder (ADHD): 22%

• • • Non-ASD: 6%

114% difference

4. Sleep-wake disorders: 21%
   • • Non-ASD: 20%

5% difference

5. Obsessive-compulsive disorder (OCD): 10%
   • • Non-ASD: 2.3%

125% difference

6. Schizophrenia spectrum disorders: 10%
   • • Non-ASD: 1.5%

148% difference

7. Impulse/conduct disorders: 7%
   • • Non-ASD: 4%

55% difference

8. Bipolar disorders: 9%
   • • Non-ASD: 4.4%

67% difference

This data reveals significant differences in prevalence between adults with and without ASD and common mental health disorders. This foregrounds the need for a greater understanding of co-occurrence between autism and other mental health disorders, which could improve overall treatment outcomes for adults with ASD and a co-occurring mental health disorder.

Now let’s look at the data for children and adolescents.

For Children and Adolescents: Autism and Mental Health Disorders

Note: diagnosis of disorders with psychotic features such as schizophrenia is very rare in children, with many experts indicating a diagnosis of psychosis in children is not feasible and subject to too many confounders for diagnostic accuracy. Diagnosing bipolar disorder in children under 13 is also rare, and subject to problematic confounders as well.

1. Attention-deficit hyperactivity disorder (ADHD): 45%

• • • Non-ASD: 11.4%

120% difference

2. Anxiety disorders: 42%

• • • Non-ASD: 41%

2.5% difference

3. Sleep-wake disorders: 30%

• • • Non-ASD: 20%

40% difference

4. Impulse/conduct disorders: 20%

• • • Non-ASD: 8%

88% difference

5. Depressive disorders: 19%

• • • Non-ASD: 15.1%

23% difference

6. Obsessive-compulsive disorder (OCD): 10%

• • • Non-ASD: 2%

133% difference

7. Schizophrenia spectrum disorders: 10%

• • • Non-ASD: ≤ 0.1%

Data on schizophrenia among youth is not reliable enough for meaningful estimate of difference.

8. Bipolar disorders: 7%

• • • Non-ASD children 6-12: ≤ 2%
    • Non-ASD adolescents 13-18: 2.9%

82% difference between non-ASD and adolescents with ASD.

This data also shows substantial differences in prevalence between children and adolescents with and without ASD and the most common mental health disorders. This data teaches us that we need to improve both our knowledge and understanding of co-occurring mental health disorders among children with autism. Expanding our awareness of and ability to support children, youth, and adolescents with autism and additional mental health disorders will not only help us improve the lives of this most vulnerable group of patients, but will also help us understand how to help them as they reach and navigate the challenges of adulthood.

How Co-Occurrence/Dual Diagnosis Affects Treatment and Support

The authors of the study published in 2023 we cite above make this important observation about the phenomenon of co-occurrence among people with autism/ASD:

“The knowledge of the prevalence of co-occurrence in autism is fundamental to set up health services, especially mental health services, for adequate screening, diagnosis, and management of these conditions in people with autism.”

We concur wholeheartedly with this observation. It’s well-known that people with autism and autism spectrum disorders can experience significant functional disability, related to:

• Differences in social areas/communication/ability to communicate effectively:
  • Problems identifying and communicating personal emotions
  • Problems in using common/typical language and communication conventions
  • Challenges understanding what others say and mean
• Differences in behavior:
  • Atypical behavior, such as repetitive, self-soothing behaviors
  • Pre-occupation with a narrow range of specific activities
  • Difficulty transitioning between activities
  • Problems with change in routine
  • Difficulty interpreting the behavior of others
• Among people with moderate to severe ASD, significant difficulty in:
  • Daily self-care
  • Typical daily activities
  • Impaired academic ability/achievement
  • Impaired vocational ability/achievement

We also know the presence of a mental health disorder alone, without the presence of autism/ASD, can also create disruption across almost all functional domains of life, including family, peer, and partner relationships, school, work, and basic self-care and self-esteem.

Therefore, when autism and mental health disorders co-occur, each can exacerbate the problems associated with the other. However, here’s something we encourage people with co-occurring ASD and mental health disorders – and their families – to learn:

With an early, accurate diagnosis and appropriate support provided by mental health professionals with specialized training and experience, most people with ASD and co-occurring mental health can manage symptoms, navigate differences, mitigate the impact of functional impairment, and live a full and fulfilling life – on terms they define themselves.

More About Autism and Neurodivergence

To learn more about autism, autism spectrum disorders (ASD), neurodiversity, and to understand what people mean when they say The Neurodiversity Movement, please read this article from the National Autistic Society in the U.K.:

The Neurodiversity Movement