Autism can be misdiagnosed as another condition, and vice versa. Here’s why that can happen.

Autism spectrum disorder (ASD) is a neurodevelopmental condition estimated to affect about 1.5% of the population. Because ASD diagnoses have increased over the past few decades, many people wonder whether autism is overdiagnosed or misdiagnosed.

There’s a lack of statistical research on how common autism misdiagnosis is. However, ASD diagnoses can be challenging for a number of reasons, making it possible for clinicians to misdiagnose people.

A number of scenarios are possible:

  • Autistic people may receive a misdiagnosis of another condition that they don’t actually have.
  • People who are not autistic may receive a diagnosis of ASD.
  • Autistic people who have another condition may not receive a diagnosis of ASD because their symptoms are attributed to that other condition.
  • Autistic people may receive a late diagnosis (delayed diagnosis).
  • Autistic people may receive no diagnosis at all (missed diagnosis).

Misdiagnoses can be harmful, as it means that a person may not receive the help and support they need.

There’s no consensus on how common autism misdiagnosis is, partly because it’s impossible to verify how many people haven’t received a diagnosis of the condition they actually have.

However, a fair amount of research highlights that it’s a common problem. In one 2021 study, over 75% of participants received an ASD diagnosis about 8 years after their first mental health evaluation.

Another study from 2019 looked at 4,498 children and found that 1,135 (25%) had symptoms of autism but didn’t have an ASD diagnosis.

Part of the reason for autism misdiagnosis is that there’s no lab test or brain scan that can be used to definitively help diagnose the condition.

Rather, autism is diagnosed based on the observation of certain symptoms. In other words, a healthcare professional observes someone’s behavior and diagnoses them based on whether they demonstrate symptoms of autism.

The challenge with this method is that:

  • Autism presents differently in different people.
  • Some people consciously “mask” or attempt to hide their symptoms in order to fit in.
  • The symptoms of autism can overlap with the symptoms of other conditions.

The symptoms of autism can be misinterpreted as the symptom of another condition or vice versa. For example, autistic people may engage in repetitive or ritualistic behaviors, which could look like an OCD-related compulsion.

Additionally, autistic people may have other neurodevelopmental conditions or mental health conditions. A study estimates that 70% to 80% of autistic people also receive a diagnosis of another psychiatric condition.

Women and autism

Gender can play a role in autism misdiagnosis. A review from 2019 found that ASD symptoms in women are more likely to be misdiagnosed. Women were more likely to receive a delayed diagnosis than men. In other words, most women had to wait longer for a diagnosis after seeking healthcare.

Several factors may contribute to this issue.

Most autism research focuses on male samples, which means diagnostic tools have been designed to look for the symptoms that are more common in men. The symptoms of ASD can vary by gender. Compared with autistic men and boys, autistic women and girls tend to have more social motivation and be less hyperactive and impulsive.

Secondly, research suggests women and girls may be more likely to “mask” their symptoms.

Lastly, gender bias can play a role in autism misdiagnosis. If parents, teachers, and clinicians assume women and girls are unlikely to be autistic, they may be less likely to suggest screening women and girls for ASD.

Language matters

We use “women” and “men” in this article to reflect the terms that have been historically used to gender people. But your gender identity may not align with how your body responds to this condition. Your doctor can better help you understand how your specific circumstances will translate into diagnosis, symptoms, and treatment.

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Alternative diagnoses

It’s possible for ASD to be misdiagnosed as another condition or vice versa.

In a study from 2020, autistic adults had previously received diagnoses for:

This is not to say that the above diagnoses were incorrect. It’s possible to have both ASD and another condition. However, ASD symptoms can overlap with symptoms of other conditions, leading to misdiagnosis.

For example:

  • ADHD and ASD have several overlapping symptoms, including difficulties with impulsivity, executive function, and hyperactivity.
  • Social anxiety disorder can look like ASD and vice versa, as autism can affect social interaction.
  • OCD and ASD can both involve repetitive behavior and rituals.
  • Sensory processing difficulties, which are prevalent in autistic people, could be misdiagnosed as schizophrenia-related hallucinations or eating disorders (when the sensory difficulty relates to food).
  • Intellectual disability and ASD symptoms can overlap, especially as they both include social differences, difficulties with executive function, and repetitive behaviors.

Autism looks different in different people. Two autistic people may have completely different traits and symptoms. Some autistic people may require more accommodations and support than others.

The common symptoms of autism include:

  • difficulty regulating emotions
  • difficulty interpreting or using nonverbal communication (such as body language, facial expressions, and tone of voice)
  • intense special interests
  • conversational styles that differ with that of most neurotypical people
  • preferring strict routines and becoming distressed when routines are changed
  • repetitive or ritualistic behaviors
  • difficulty processing sensory input (for example, becoming easily overwhelmed in noisy spaces)

It’s possible for autistic people to not have one or more of the above symptoms.

When someone receives the incorrect diagnosis, they might not get the treatment and support they need.

This can affect their:

  • executive function (that is, their ability to start and complete day-to-day tasks)
  • self-esteem and self-image
  • relationships
  • schooling/career

In cases where people are prescribed medication for conditions they don’t actually have, there’s a risk that they experience side effects without benefitting from the medication.

Consequences of late autism diagnosis

A 2022 study found that autistic children with a late diagnosis often have difficulties with mental health and relationships before their diagnosis. These problems can become more severe into their adolescence.

Another recent study looked at the consequences of late autism diagnosis in men. It found that a lack of diagnosis significantly affected their understanding of themselves. Many of the participants also had difficulties in their relationships and careers as a result. Some participants developed potentially harmful coping mechanisms.

If you think you or your child has received a misdiagnosis of ASD, or if you think you or your child is autistic but haven’t received a diagnosis, you can reach out to a specialist.

Usually, your doctor is the first port-of-call for screening for ASD. If you disagree with your doctor’s conclusion, you can seek a second opinion from another doctor or ask to be referred to a specialist.

When discussing a potential diagnosis, it might be helpful to:

  • Explain why you think you/your child received a misdiagnosis.
  • Specify which symptoms may have led to a misdiagnosis.
  • List the symptoms that could explain which condition you/your child may have.

If you believe your doctor or healthcare professional is biased or dismissive of your concerns, it may be wise to seek a second opinion.

Although there’s no consensus on how common autism misdiagnosis is, it can happen. It’s possible to receive a misdiagnosis of ASD when you don’t have it, and it’s possible to have ASD but have your symptoms overlooked.

Some autistic people cope without having an official diagnosis from a healthcare professional. However, a diagnosis can help you find the support you need to thrive.

If you believe you or your child has received a misdiagnosis, consider getting a second opinion.