From DSM-IV to DSM-5: What Changed in the Diagnosis of Autism?

Since 2013, the diagnosis of autism has changed significantly with the adoption of the DSM-5. The previous category of Pervasive Developmental Disorders was replaced by Autism Spectrum Disorder (ASD), unifying diagnoses such as autism, Asperger's syndrome, and PDD-NOS.

The diagnostic criteria were reduced from three to two core areas:

• Deficits in social communication and interaction

• Restricted and repetitive patterns of behaviour, interests, or activities

What does this change mean in practice?

The diagnosis is now provided with specifiers instead of separate subcategories, allowing for a more individualised description of each person’s profile, such as:

• Level of support required (levels 1–3)

• Presence or absence of language and/or intellectual difficulties

• History of regression

• Co-occurring medical or psychiatric conditions

This approach recognises autism as a spectrum with diversity in how it presents. Diagnosis becomes both more flexibleand structured, enabling a more accurate assessment of support needs.

But there’s also a challenge…The broader and more flexible diagnostic approach can lead to overdiagnosis if the criteria are applied without adequate clinical judgment regarding support needs, or without considering the person’s broader life context.

What’s the difference between the terms "neurodivergent" and autism?

The term neurodivergent is not a diagnostic label. It is a social and descriptive term used to acknowledge different neurodevelopmental profiles — such as autism, ADHD, or dyslexia — without framing them as pathological.

In contrast, an autism diagnosis under the DSM-5 is a medical classification, used to access support, interventions, and entitlements.

In summary:

All individuals with an autism diagnosis are neurodivergent.But not all neurodivergent individuals have or need a diagnosis.

Where do we draw the line? At the diagnostic/clinical level:

A diagnosis requires that the person experiences functional challenges in daily life (e.g., in social relationships, work, or independent living) that justify systematic support.

At the descriptive/identity level (neurodiversity):

A person may have neurodevelopmental differences without meeting clinical criteria or needing intervention. This term respects diversity without assuming "pathology."

So, the diagnostic line is not simply about being different, but about whether that difference causes significant difficulty in life (a form of socio-emotional disability).

For health professionals, educators, and caregivers, understanding these distinctions is crucial. They help us approach each person with respect for their individuality and offer support that is meaningful, not stigmatising.