Signs of Autism in Teens

Written by Dr Lucy Russell DClinPsyc CPsychol AFBPsS
Dr Lucy Russell Founder of They Are The Future
Author: Dr Lucy Russell, Clinical Psychologist

Signs of autism in teens who do not (yet) have an autism diagnosis are likely to be subtle.

If the signs were not subtle, they would probably have been picked up and assessed at an earlier stage in your child’s development.

The signs often come to the surface in the early teenage years.

Autism is my specialism and it runs in my family.

At Everlief, the child psychology clinic I run with my husband Mike, we specialise in working with older children who have subtle traits of autism. My team and I carry out autism assessments. In particular, my team and I assess many teen girls for autism. We also offer follow-up support to families and young people, including therapeutic support.

Often they have reached age fifteen plus before someone flags that they may be autistic. Commonly, it is the teen themselves who has figured it out and has done a lot of research.

I will run through the common signs of autism in teens, and how to support a teen with autistic traits, whether or not they have an autism diagnosis.

In the latter part of the article I’ll shine a spotlight on symptoms of autism in teen girls, as autism traits in girls are often much misunderstood.

What are the Main Symptoms of Autism in Teens?

Unfortunately autism is often referred to as a neurodevelopmental disorder or a “condition”, but in my service we explain autism as a difference.

This difference can bring many strengths as well as difficulties.

A lot of the difficulties are caused by the way the world works, rather than a fault within the autistic individual.

That being said, the key traits of autism are:

  • Social communication difficulties (e.g. reading and using body language/facial expression, generating two-way conversation).
  • Difficulties with social imagination (e.g. making inferences, predicting what might happen next in a social interaction).
  • Repetitive behaviours and intense interests.
  • Sensory processing differences (such as sensitivity to sounds).

If a teen is autistic there will have been signs early on in their development. But, with so-called “milder” autism these may have been so subtle that they are only spotted in hindsight, making an early diagnosis impossible.

an autistic teenage boy enjoying the outdoors

Though autism is considered a lifelong condition the “symptoms” of autism are now considered much more fluid than we first thought. In other words, they can change over time.

For example, specific social skills can improve a lot with practise and/or coaching (though the person may still find socialising exhausting, so social “skills training” should never be forced on someone).

Also, the signs of autism are more obvious when a person is under stress.

That’s why children often fall under the radar during primary school, but their autistic traits are more noticeable when faced with the increased demands of secondary school.

What are the Specific Signs of Autism in Teens Which May Go “Under the Radar”?

Often the early teenage years are a “perfect storm” when it comes to the emergence of  autistic traits.

Where these may have been mild or hidden in young children, they often now start to bubble up to the surface.

The following are some of the reasons why:

  • Puberty: Hormonal changes and identity exploration.
  • Academic pressure as the child advances through high school.
  • Increasing gap between the teen and their peers (for example, social relationships become more complex and they struggle to keep up).
close up of a teenager writing with pencil and paper at a desk

Here are some of the issues teens may face which means they may not get the support they need straight away:

“Hidden” Autism Symptoms in Teens

1. They Appear “Fine” in Class But They Are Only Just Coping

The first “hidden” autism symptom in teens that I see over and over in my clinic is that your child seems fine in class, but in fact their stress levels are through the roof.

This has nothing to do with intelligence. Autistic brains and neurotypical brains work in different ways. Autistic people may need adaptations in teaching style in order to achieve their potential in a school environment.

Perfectionism (e.g. having to re-draw a diagram over and over until it is “right”), slower processing speed, difficulty filtering out background noise, difficulty with inferences, or difficulty following multi-part instructions can make learning overwhelming and exhausting.

a teen girl at school sitting at a desk

Autistic people also tend to have a hard time managing unlimited/too many choices, so open-ended or unstructured tasks can be a nightmare for some.

If group or partner work is required, the additional social communication demands can be too much for some teens.

Most teens with autistic traits won’t experience all of these issues, but most will experience at least one.

2. Autistic Teenagers May Mask Their Sensory Difficulties

If you have a sensitive startle response to light touch and twenty people brush past you in the corridor, your nervous system will become overloaded within minutes.

If you find loud noises hard to bear, the sound of the school bell ringing all day may send you to breaking point.

Having to wear a scratchy school blazer all day and shoes that feel too tight might cause a constant sense of high stress.

an autistic teenager sitting by water, serious, reflective

Every teen’s sensory profile will be different but often the adults around them are completely unaware.

To make things even more complex, sometimes the teen themselves is not aware, until they reach their limit.

Chronic sensory overload is a symptom of autism in teens that I see every day in my clinic. It is also one of the most common risk factors for mental health issues in autistic people.

3. Overlooked Autistic Teens Often Appear Skilled at Social Interactions But May Actually Struggle

Often teenagers and young adults who come to my clinic appear to be in one of three “camps”.

The first group is those who have a happy, close group of friends with whom they can truly relax, but outside of this group they find interactions unpredictable and exhausting.

a group of young teenagers gathered around a computer

The second group is those who have people they “hang out” with but desperately crave closer relationships and friends they can be themselves around.

The third group is those who find nearly all interactions stressful, and need more personal space and quiet time than neurotypical teens. They may even enjoy social interactions, but their “social battery” gets easily drained. This group may or may not feel lonely.

In each of these groups teens may find it difficult to connect emotionally with others and may feel a sense of social isolation. They may for example notice that someone is upset, but be unsure how to respond.

You can read more about how to support your child with friendships in my article: Autism And Relationships: Supporting Young People.

4. A Telltale Symptom of Autism in Teens is That They Find it Harder to Describe and Understand Their Emotions

Not only do some teens have difficulty understanding and describing emotions, but some also have less awareness in the body of the emotion and the accompanying physical sensations. This is part of something called interoception.

It means that autistic teens can be incredibly stressed but not fully realise it until they explode or break down. There are strategies we can use to help.

Diagram: What sad feels like for Sadie, an autistic teen girl

Psychologists often use visuals to create concrete descriptions and images of emotions. They also like to create personalised “roadmaps” of what that emotion might feel like as it builds up. These visuals work brilliantly with both younger children and teenagers.

5. Stress, Anxiety and Depression Can Be Underlying Signs of Autism in Teens

If life is constantly socially demanding and sensory information is overwhelming, this can cause chronic mental ill-health and can contribute to physical ill-health.

Teenagers with autism and autistic traits are more likely to experience mental health difficulties than their neurotypical peers.

sad teenage boy on his bed holding a pillow

Chronic stress is a risk factor for physical ill-health too. One reason is that cortisol (the stress hormone) causes inflammation in the body and negatively impacts the immune system.

Feeling stressed all the time is exhausting and deflating. This (and other factors) can lead to low mood or depression.

Anxiety, however, is probably the most common mental health issue in autistic teenagers. If you want to know how to support your anxious teen, read my article: Autism And Anxiety: Supporting Children In An Imperfect World.

Spotting Autism Signs in Teens: What To Do Next

You may have spotted signs of autism in your teen over a long period of time. It’s natural to want to push it away and a period of denial is completely normal. Though autistic people can be very successful and happy, life as an autistic person can also present challenges in everyday life, and nobody wants their child to have to face extra challenges.

Autism Symptoms in Teens: Should You Seek an Assessment?

I spend a lot of time discussing the pros and cons of having a label or diagnosis, with both parents and teens themselves.

It’s different for everyone.

For some teens, knowing they are autistic helps them understand themselves, feel positive about their identity and make plans for the future.

For others, now is not the right time to seek a diagnosis but it is something they can return to in the future.

On balance though, most teens do benefit from an assessment. Understanding their symptoms of autism and their autism-related strengths can be empowering and can be a great relief.

My Teen Only Has Mild Autism Symptoms: Is a Label of Autism Helpful?

It’s so helpful if you and your teenager can have open discussions about their autism traits.

What might be the potential benefits of an official diagnosis for them?

What additional support or understanding do they need?

What support could they get if they decided not to seek an assessment?

What additional support might they get if they had a diagnosis?

Do consider though, that the idea of mild autism symptoms can be misleading. As already discussed, some people are very good at masking. So their autism symptoms may seem mild but in reality they could be taking a huge toll on mental health.

Autism is multi-faceted. Therefore even though you may feel that your child has mild autism symptoms in some areas (e.g. social interaction) their symptoms in other areas may affect them more (e.g. sensory processing).

Symptoms of Autism in Teens: Top Tips From a Child Psychologist

Here are some expert tips for supporting teens with autistic traits while they await an autism assessment or whilst you gather evidence or consider the merit of an autism assessment.

1. If There Are Traits, Treat as Autism

Early intervention is crucial for a child to thrive.

a mother and teenager eating, drinking and chatting in a kitchen

There is nothing to be lost by assuming a child is autistic if you have observed autism symptoms. This will allow you to take a step back and view the child from a different perspective, considering what individual needs they may have.

You may wish to consider our fantastic online parent course, Embracing Autism.

2. Look Below the Surface for Underlying Autism Symptoms

In school but sometimes at home too, many autistic children mask their difficulties in order to fit in or because they are scared of being told off.

By the time children become teens they may be masters of masking.

happy teenage girl

For instance, they may nod that they have understood a complex instruction, rather than admit that the instruction was given too fast for them to keep up.

They may laugh along with a joke even though they don’t understand why it’s funny, to fit in.

3. Look Beyond the Stereotypes of Autism

There are many stereotypes about autism. Often these are based on one particular group of people with autism and are not reflective of teens with subtle signs of autism.

For example, just because someone can give eye contact, this does not mean they are not autistic.

They may have practised hard at using eye contact, or they may only use eye contact in some situations. Or maybe eye contact is not actually difficult for them, but other areas of social communication are.

two teen boys sitting on a step looking at their phones

Similarly, just because a teenager has friends, it does not mean they are not autistic. They may (sometimes with difficulty) be able to “do” one-to-one or small group friendships successfully but find larger groups stressful.

Some teens may find that they have a friendship group, but they feel they have to work very hard to maintain it and find it exhausting. Others may feel a sense of detachment from their peers or feel on the edge of friendship groups.

4. Encourage Increased Rest and Down Time to Support Your Teen’s Autism Symptoms

Teens with autism or autistic traits will almost always need to have more down time or rest than neurotypical teens.

Down time is difficult to define as it is so different for every child. It involves giving the nervous system and brain a break to recover from overstimulation and too much demand.

sleepy teen girl on bed with a book

Examples might include:

  • Using a time out card or exit pass to take a break from the classroom.
  • Going to a quiet space to listen to soothing music.
  • Engaging in deep pressure activities (such as pressing against a wall) or activities which stimulate the vestibular system (such as swinging) to regulate the nervous system.

When they get home from school students are often exhausted from their sensory sensitivities, academic and social demands.

They need sufficient time to decompress before any demands are placed on them. This includes homework. I suggest a minimum of one to two hours.

Rest is an essential part of a healthy lifestyle and is one of the protective factors against mental health problems.

Read more about lifestyle and mental health in my article: Child Mental Health: The Lifestyle Connection

5. Be Flexible With Your (Potentially) Autistic Teen

Teenagers with autism or traits of autism need the system around them to be flexible.

For instance, just because most children in UK schools take 10 GCSE exams, this does not mean it is right for every child.

If you have a slower processing speed or sensory overwhelm in the classroom, it can be a massive relief to drop a subject or two.

This allows for free periods to catch up in other subjects and to decompress from overwhelm.

teenager sitting down listening to music through headphones

As another example, most students are expected to attend assemblies but the cons of attending assemblies may outweigh the pros for some autistic teens.

6. Be Subtle About Ways of Managing Your Teenager’s Autism Symptoms

In the teenage years, fitting in is often of utmost importance to children. Be aware that some of the suggestions you make will not be acceptable to many autistic teens, if they involve being openly treated as “different”.

For example, if your teenager finds loud noises overwhelming when out and about, one strategy would be to wear noise-cancelling headphones. But some teens refuse to do this because they don’t want to stand out. This can feel frustrating for parents, but sometimes we need to think outside the box and find more subtle strategies.

It goes without saying that you also need to respect your teen’s wishes regarding who to tell about your teenager’s autistic traits.

You may feel it would be helpful for extended family members to know that they are awaiting an assessment, but your teen may want to keep this information to themselves for now. After all, they are still processing everything.

7. Be Consistent

It’s incredibly important that parents and all teachers have a shared understanding of what works for an autistic individual. This means it’s important to have a higher level of communication between home and school, and between teaching staff.

This is the case even if a child appears to be coping.

Many autistic girls in particular will remain under the radar despite experiencing very high stress at school.

autistic teenager and learning mentor

The most successful strategy I have come across is as follows:

  • A key member of staff (in the UK this is often the SENDCo or Head of Year) has daily or weekly communication with parents.
  • This member of staff “checks in” with the child regularly at school (at least once a week) and establishes a rapport.
  • The child has a written plan (to which they have contributed) outlining their needs in one A4 page e.g. “These are the areas I find difficult and this is what works for me.” This is shared to the form tutor and all subject teachers. It is updated once a term.
  • The key member of staff shares any immediate issues or concerns with subject teachers and vice versa. They adopt a flexible, problem-solving approach.

8. Increase Your Knowledge

Spotlight on Symptoms of Autism in Teen Girls

Autism can sometimes be harder to spot in teen girls. Some autistic teen girls seem to be very good at appearing to fit in with others. Their interests may seem mainstream and similar to their peers. However, it’s often the intensity with which they follow their interests that stands out.

Autism Symptoms in Teen Girls: Case study – Hannah Aged 14

Hannah, a bright and creative 14-year-old girl, is an example of how autism symptoms in teen girls can manifest in subtle yet impactful ways.

Hannah’s journey showcases the challenges and strengths that can come with having autism traits that often go unnoticed.


Hannah has always been considered a quiet and well-behaved child. Growing up, she displayed a keen interest in art and literature.

While she was able to maintain a small group of friends, she struggled to initiate conversations and connect with peers on a deeper emotional level.

Her parents and teachers often attributed her quiet demeanor to shyness or introversion.

Intense Interests and Social Struggles

As Hannah entered her teenage years, her intense interests in art and literature became more pronounced. She could spend hours immersed in drawing, painting, and writing stories.

While her passions were admirable, her focus on these activities sometimes made it difficult for her to engage in typical social interactions.

Hannah’s interactions with her classmates often felt awkward and strained. She struggled to understand the unwritten rules of social behavior, leading to moments of isolation during group activities.

Despite her longing for closer friendships, Hannah found herself feeling overwhelmed and drained by prolonged social interactions, and she often preferred to spend time alone.

Masking and Social Camouflage in Autistic Teenage Girls

Hannah’s ability to mask her difficulties in social situations was remarkable. She had learned to maintain eye contact and imitate social cues to fit in, but these actions required significant effort and energy.

Her parents noticed that she would often come home after school visibly exhausted, as if holding herself together throughout the day had taken a toll on her.

Sensory Sensitivities as Autism Traits in Girls

Hannah’s sensory sensitivities were another aspect of her life as an undiagnosed autistic teenage girl.

She had a strong aversion to scratchy fabrics, and the bustling hallways of her school often overwhelmed her.

The sounds of school bells and the constant chatter of students left her feeling on edge.

Despite her struggles, Hannah never vocalized her discomfort, fearing that it would make her stand out even more.

Emotional Awareness and Self-Expression Difficulties: Autism Symptoms in Teen Girls

One of the most challenging aspects for Hannah was understanding and expressing her emotions.

She often found it hard to put her feelings into words and struggled to recognize the physical sensations that accompanied her emotions.

This difficulty sometimes led to sudden outbursts of frustration or meltdowns when her emotional state became overwhelming.

Seeking Support for Autism Signs in Teenage Girls

Recognizing that something more than shyness was at play, Hannah’s parents decided to seek professional guidance.

Through an assessment conducted by a clinical psychologist and her team who specialized in autism, Hannah was diagnosed with autism spectrum disorder. This diagnosis provided her and her family with a better understanding of her struggles and strengths.

Benefits of Diagnosis of Autism in Teen Girls

The diagnosis allowed Hannah and her family to explore strategies that would help her navigate her challenges more effectively.

She began working with a therapist who focused on building her social emotional confidence and emotional regulation skills.

Hannah’s diagnosis also offered a sense of relief, as she now had an explanation for the difficulties she had faced.

What Does A Supportive Environment Look Like For Autistic Girls?

Hannah’s school collaborated with her parents to create an Individualized Education Plan (IEP) that included classroom accommodations to address her sensory sensitivities and social communication difficulties.

Her teachers received training on recognizing and supporting autistic students, to create a more inclusive environment. For many years they had thought she was shy, but since learning about masking they could recognise when Hannah wasn’t coping or needed extra support.

Autism in Girls: Embracing Identity

With the knowledge of her autism diagnosis, Hannah began to embrace her unique identity. She found solace in connecting with online communities of young autistic women who shared similar experiences.

She discovered young female autistic role models such as Siena Castellon.

Through art and writing, Hannah had a powerful outlet for expressing her thoughts and emotions.

Moving Forward

As you can see, Hannah’s journey demonstrates that autism in teen girls can present differently from traditional stereotypes.

While she faced challenges in social interactions, sensory sensitivities, and emotional expression, she also possessed a deep passion for her interests and a remarkable ability to adapt to social situations.

With the right support and understanding, Hannah continues to thrive, using her creativity and insights to make her mark in the world.

How You Can Support Your Autistic Teenage Daughter

Watch this presentation by female autism advocate Siena Castellon on How You Can Support Your Autistic Teenage Daughter, even if they haven’t been diagnosed yet.

YouTube video

Frequently Asked Questions

What are the 3 main symptoms of autism?

When we assess for autism we are looking for:

  • Differences in social communication and interaction (e.g. struggling to pick up important social cues or misreading body language, tone of voice or facial expressions).
  • Repetitive or obsessive behaviours and rigidity of thinking.
  • Sensory processing differences (for example, sensitivity to noise or certain textures).

How do You Know if a Teenager is Autistic?

Even as a parent, you don’t always know. But if your child has difficulties with social communication and interaction, has repetitive behaviors or intense interests, and sensory processing differences, they may be autistic.

Keep a diary or notebook over a few months of traits you have spotted. Then take some time to talk through your concerns, perhaps with your family doctor.

What Does Autism Look Like in a Teenager?

There is no specific way that autism “looks” in a teenager. It’s different for every teen. Some teens may be very outgoing and gregarious, yet lack subtle social skills. Others may appear withdrawn and highly anxious in social situations.

What is High Functioning Autism in Teenagers?

High functioning is a term that used to be used for autistic people with average or above average IQs, such as children in mainstream schools. It is no longer an accepted term. We now recognise that autism is multidimensional. Just because a person is “high functioning” in one area, doesn’t mean they are not struggle in another.

Another term previously used was Asperger’s syndrome. This term is still preferred by some autistic people, but it is no longer a specific diagnosis in the diagnostic manuals. Children who would previously have been diagnosed with Asperger’s syndrome would now receive a diagnosis of autism.

Is there a “Teenage Autism Test”?

There is no single test. Clinicians sometimes do screening questionnaires but these cannot give a diagnosis. A typical assessment may consist of:

  • DISCO (Diagnostic Interview for Social and Communication Disorders).
  • ADOS (Autism Diagnostic Observation Scale).
  • Occupational therapy or speech and language therapy assessment
  • School observation.

Learn more about autism assessments in my article: Autism Assessments: Information For Parents.

Dr Lucy Russell is a UK clinical psychologist who works with children and families. Her work involves both therapeutic support and autism assessments. She is the Clinical Director of Everlief Child Psychology, and also worked in the National Health Service for many years. In 2019 Lucy launched They Are The Future, a support website for parents of school-aged children.

Through TATF Lucy is passionate about giving practical, manageable strategies to parents and children who may otherwise struggle to find the support they need.

Lucy is a mum to two teenage children. She lives in Buckinghamshire with her husband, children, rescue dog and three rescue cats. She enjoys caravanning and outdoor living, singing and musical theatre.

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