1.1 Describe the main diagnostic features of autism spectrum condition

This guide will help you answer 1.1 Describe the main diagnostic features of autism spectrum condition.

Autism Spectrum Condition (ASC) is a lifelong developmental condition that affects how people communicate, interact, and experience the world. The word “spectrum” means that autism presents itself in many ways. Everyone with autism is unique and their strengths and needs can vary. Diagnosing autism relies on recognising certain patterns of behaviour and development, particularly in social communication, interaction, and restricted or repetitive activities. Professionals use diagnostic tools like the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th edition) or the ICD-11 (International Classification of Diseases, 11th edition) to help identify whether a person is autistic.

Diagnostic of Autism Spectrum Condition

People receive a diagnosis of autism through a structured assessment by a specialist team, such as a child development specialist, psychologist, or psychiatrist. These experts look at the main features set out by clinical guidelines. The diagnostic features fall into two broad areas:

• Difficulties with social communication and social interaction
• Restricted, repetitive patterns of behaviour, activities, or interests

It is also recognised that these differences appear from early childhood, even if the features may become more noticeable or relevant as demands increase later in life.

Difficulties with Social Communication

Social communication means the way someone understands and uses language to interact with others. People with autism can have marked differences in both verbal and non-verbal communication. Below are some points on how this may show up in daily life:

• Difficulty with conversation: This can mean struggling to start or maintain a chat, or not knowing when to take turns.
• Literal understanding: Sarcasm, jokes, or implied meanings may be hard to grasp.
• Unusual use of words: Some may echo words or repeat what others say, known as echolalia.
• Tone and pitch: The way someone speaks might sound flat, sing-song, or unusual.
• Non-verbal signals: Reading body language, facial expressions, or gestures can be difficult.

Some children may not develop spoken language at all. Others may have rich vocabularies but find it hard to use language socially. For adults with autism, workplace chats or public events can feel overwhelming or confusing if they struggle to “read the room” or pick up social cues.

Difficulties with Social Interaction

Social interaction covers relationships and the social rules that most people learn by watching others. For people with autism, these rules do not always come naturally. This can affect how they build friendships or relationships, or how they respond to or show emotions. Key points include:

• Difficulty making or keeping friends: They may find group activities stressful or not know how to join in.
• Limited or unusual eye contact: Some people may avoid eye contact, while others might stare.
• Joint attention struggles: Joint attention is when two people focus on the same thing and share that interest. It might be hard for someone with autism to point out or show things to others, or to respond when someone else does.
• Understanding emotions: Both their own and other people’s feelings can be hard to identify or express. They may not respond in expected ways to other people’s emotions.
• Preference for routine: Sudden changes in social situations may cause anxiety or withdrawal.

Some people with autism might wish to connect with others but do not know the accepted ways to show this. Others might not have the same drive or interest in forming connections as most people.

Restricted, Repetitive Behaviour and Interests

A big part of the diagnosis looks at interests and actions. People with autism often show repetitive behaviours or have intense, special interests. These features can include:

• Repetitive movements: Such as hand-flapping, rocking, spinning, or tapping.
• Repetitive use of objects: Lining up toys, spinning wheels, or opening and closing doors many times.
• Rigid routines and rituals: Insisting on eating the same food, taking the same route to school or work, or wanting things just so.
• Distress at change: Strong discomfort if routines are changed or unexpected events happen.
• Intense interests: Focusing deeply on a particular topic, subject, or object, sometimes for hours on end. This can range from train timetables to types of insects or collecting certain objects.

These behaviours are not always negative. Special interests can give comfort, skill, or pleasure. However, distress or anxiety often arises if the pattern is broken or if the person cannot access their interest.

Sensory Processing Differences

Many people with autism have differences in how they process sensory information. This can mean being much more or much less sensitive to sights, sounds, touch, tastes, smell, pain, or temperature. Some examples:

• Over-sensitivity: Everyday sounds—like hand dryers, sirens, or crowded rooms—can feel painfully loud or distressing.
• Under-sensitivity: High pain threshold, strong tastes, or enjoyment of bright lights and strong smells.
• Touch: Some people avoid hugs or have strong reactions to clothing labels.
• Filtering: Finding it hard to ignore background noise or becoming overwhelmed in busy places.

These sensory differences can affect behaviour, mood, and participation in daily life. These features are now recognised in some diagnostic tools as important but are not currently a core feature in all checklists.

Early Onset and Lifelong Impact

Diagnosis explores whether these features have been present from early development, not arising later as a result of specific events or injuries. Many parents notice differences in their child’s behaviour, play, or development from toddler years. For some, these features may become clearer only when social demands in school, work, or public life increase.

Autism is considered a lifelong condition, but people’s needs, strengths, and difficulties can change over time. The impact of the diagnostic features varies from person to person.

Variation Within the Spectrum

It is important to remember everyone with autism is an individual. The intensity, combination, and effect of each feature differ for each person. Some people may live very independently, while others need support throughout life. Labels like “high-functioning” or “low-functioning” are now discouraged, as they do not capture the unique mix of abilities and needs.

Comorbidities and Overlap with Other Conditions

Many people with autism have other conditions too. This is known as comorbidity. Common overlapping conditions include:

• Attention Deficit Hyperactivity Disorder (ADHD)
• Anxiety or depression
• Learning disabilities or learning difficulties
• Epilepsy
• Dyspraxia (affecting movement and coordination)
• Sensory processing disorder

These other conditions can affect how autism presents and can make assessment more complex.

Changes in Diagnostic Criteria

The way autism is diagnosed has evolved over time. In the past, people were described as having “Asperger syndrome”, “classic autism”, or “pervasive developmental disorder not otherwise specified (PDD-NOS)”. The DSM-5 and ICD-11 have replaced these with a single label: Autism Spectrum Condition. This shift reflects the wide range of features and avoids ranking one presentation as more or less severe than another.

Recognising Autism in Females

Autism has often been recognised more in boys than girls. Recent research shows girls can present differently. They may mask their differences, copy peers, or have less obvious repetitive behaviours. Their special interests might go unnoticed, as they are not always outside the typical range. Assessment professionals now take care to search for these features in girls and women, as they may be missed by traditional checklists.

Key Points in Diagnosis

A diagnosis of autism requires:

1. Clear differences or difficulties with social communication and interaction
2. Restricted, repetitive behaviours or interests
3. Features present from early childhood, even if recognised later
4. Significant impact on life, work, or relationships

Assessment will include:

• Interviews with the person and family
• Observing behaviour in different settings
• Using assessment tools and checklists
• Gathering information from schools, workplaces, or care settings

Diagnosis is not always straightforward. Signs might be masked, especially in adults or those with high intellect. Some people are diagnosed in early childhood; others only come to professional attention in adolescence or adulthood.

Final Thoughts

Understanding the main diagnostic features of autism helps workers recognise the strengths and challenges faced by autistic people. By focusing on social communication and interaction, repetitive patterns of behaviour, and possible sensory differences, we can see what makes someone eligible for a diagnosis. Each person’s autism will look different and present its own opportunities and challenges.

Early and accurate diagnosis can guide the right support and adjustments. This understanding improves wellbeing, opens doors for opportunities, and encourages inclusion in society. By keeping these diagnostic features in mind, you can better support individuals to live their fullest lives and feel valued for who they are. Your knowledge makes a positive difference every day.