Is It Autism? Understanding Early Diagnosis in Children Under 3

One of the hardest parts of my job is often being the first person to raise concerns about Autism. Because I provide direct services almost exclusively, I’m usually the first professional my families turn to after the diagnosis. Just like children with Autism, every family’s experience with the diagnosis is different. Some parents feel relief because they’ve struggled to understand why their child has had such a hard time regulating, while others are upset, especially when they didn’t expect the diagnosis, particularly at such a young age—sometimes as early as 18 months. As a trained professional, I can typically identify signs within just a few minutes of meeting a child.

To better understand the diagnosis and what it looks like in toddlers, I wanted to go over the DSM-5 diagnostic criteria:

A. Persistent deficits in social communication and social interaction across multiple contexts, as manifested by all of the following:

Deficits in social-emotional reciprocity: Most neurotypical children love to interact and will actively seek out their parent’s attention. Toddlers on the spectrum often have less interest in interacting with others and struggle with joint attention. As they get older, this manifests in difficulties with back-and-forth conversation, reduced sharing of interests or emotions, and a lack of response to social cues.
Deficits in nonverbal communicative behaviors used for social interaction: A major red flag for toddlers is if they do not respond to their name by 18 months. In fact, most kids typically develop this skill around 6-9 months. Additionally, toddlers may have decreased eye contact or exhibit a gaze as if they are looking through you. Imitating gestures, like waving “bye” or using gestures to communicate (such as pointing), may be difficult for a toddler on the spectrum. You may also notice a flat affect, where the child doesn’t express themselves with their face. As they get older, they may struggle to interpret facial expressions and body language.
Deficits in developing, maintaining, and understanding relationships: Toddlers with autism tend to be more self-directed and prefer to play alone. As they get older, they may struggle to adjust their behavior in different social contexts, have difficulty sharing imaginative play, or show a lack of interest in peers.

B. Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following:

Stereotyped or repetitive motor movements, use of objects, or speech: This includes repetitive body movements (e.g., hand-flapping), repetitive use of objects (e.g., lining up toys), or echolalia (repeating words or phrases).
Insistence on sameness, inflexible adherence to routines, or ritualized patterns of behavior: This can manifest as distress at small changes in routine, difficulty with transitions, or rigid thinking patterns.
Highly restricted, fixated interests that are abnormal in intensity or focus: An individual may have an intense focus on specific topics or hobbies that are not typical for their age or development.
Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment: This may include extreme reactions to lights, sounds, textures, or an unusual interest in sensory stimuli, like smelling objects or mouthing objects obsessively.

C. Symptoms must be present in the early developmental period (typically recognized before age 3), although they may not fully manifest until later when social demands exceed limited capacities.

D. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.

E. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay.

If there is an intellectual disability or developmental delay, the social communication and behavioral impairments must exceed those expected for the level of intellectual functioning.

Specifiers:

To help with a more precise diagnosis and better understand the range of the disorder, additional specifiers can be used, such as:

Severity level (Level 1, 2, or 3) based on the amount of support needed.
Presence of intellectual or language impairment.
The presence of any associated medical or genetic condition (e.g., Fragile X syndrome, Rett syndrome, etc.).
With or without accompanying intellectual impairment.

This set of criteria helps clinicians identify the severity and characteristics of autism, ensuring a more accurate diagnosis tailored to the individual.