Understanding The Impact of Undiagnosed Autism in Adults

James Hourihan, Author

It is estimated there are 700,000 adults and children in the UK with autism spectrum disorder (ASD), a neurodevelopmental condition that affects social communication, behaviour, and sensory perception. 

While there is a big focus on diagnosing and treating children with ASD, there are many individuals who go undiagnosed with autism until later in life. Astonishingly, in July 2022, around 125,000 people with a ‘suspected autism’ referral were waiting for a diagnosis – and 84% waited for more than 13 weeks to even get their first appointment. This delay can often lead to significant developmental challenges, which have a tremendous impact on a person’s health, social and professional life.

Today, we’ll explore the signs and challenges commonly experienced by individuals on the autism spectrum to raise awareness of the vital role early diagnosis plays in improving their well-being and quality of life.

Common Signs and Symptoms of Autism in Adults

Autism is a multifaceted condition that affects individuals differently. With its complex nature, each person can have varying degrees of social, communication and behavioural challenges. 

Some of the most common signs in adults include:

  • Social difficulties, including trouble reading facial expressions, missing social cues and problems with conversation
  • Strong interest in a particular subject or topic
  • Restricted and repetitive behaviours (i.e. stimming) 
  • Difficulty with transitions or changes in routine
  • Hyposensitivity and or hypersensitivity to certain stimuli

Many autistic adults are not diagnosed at an earlier age because their cases weren’t obvious at the time. Symptoms may be subtle or easily explained away as shyness or eccentric behaviour. Additionally, doctors and psychologists sometimes misdiagnose a child or young person with autism as having a language delay or ADHD. 

More and more research is also highlighting that girls are frequently being missed or misdiagnosed until reaching adulthood. It’s estimated that for every four boys diagnosed with autism, only one girl is. This discrepancy could be due to a number of factors, including social norms that encourage girls to conform and ‘mask’ their differences, a lack of understanding of how autism presents in females, and biases in diagnostic tools that were developed based on studying boys.

The Challenges Faced by Undiagnosed Autistic Individuals

Undiagnosed autism in adults can have many negative consequences on overall wellness, social interactions, and daily activities, leading to a sense of frustration and overwhelm. Autistic individuals may struggle with a range of issues across various domains of their lives. For example: 

  1. Negative Mental Health Outcomes

Undiagnosed autistic individuals are more susceptible to developing mental health conditions such as anxiety, depression, and low self-esteem because they find it hard to express their emotions and connect with their peers, which can induce further withdrawal. 

  1. Social Isolation

People who aren’t diagnosed may experience difficulties in forming and maintaining relationships. Communicating their feelings, preferences, interests, and needs effectively is often a daunting task, leaving them vulnerable to bullying, social exclusion, and feelings of loneliness. 

  1. Employment Issues 

Undiagnosed autism can pose unique challenges for adults in the workplace. Sensory sensitivities to noise, difficulty with social nuances, and the ability to work in teams may impede productivity and job performance, making it difficult to secure or retain jobs. 

  1. Safety Risks 

Unfortunately, undiagnosed autistic adults are more at risk of abuse, neglect, exploitation and encounter dangerous situations due to impaired judgement, making them more liable to being taken advantage of and may struggle to identify red flags in interpersonal relationships.

How We Can Help 

As we continue to learn more about ASD and how it affects different groups, it’s important that we work to raise awareness and ensure that all individuals, regardless of gender, are able to access the support they need to thrive for greater inclusivity and accessibility. 

At Timian, we assist organisations in gaining a comprehensive understanding of the people they support with challenging behaviours. This includes recognising their distinctive strengths and challenges, as well as knowing how their condition affects the way they interact with the world.

Partnering with us provides invaluable insights for person-centred care. By identifying autistic characteristics early, our positive behaviour management training helps inform assessments and de-escalation strategies designed to improve communication, manage difficult situations confidently and safely, and foster positive outcomes for both children and adults on the autism spectrum.

Discover more about our courses by calling 0800 987 4075 or submitting a form on our website here. Let’s make a difference together. 

James Hourihan MSc Econ | FRSA | MIOD


Timian Learning and Development


Sign up to our newsletter to receive our helpful learning resources for free

Further Reading From Timian