ADHD vs Autism: How to Tell the Difference (Singapore)

A doctor or teacher mentioned that your child's behaviour "could be ADHD, or it could be autism — possibly both," and now you're trying to make sense of two labels that seem to describe overlapping things. Your child has trouble focusing, gets overwhelmed in noisy places, struggles socially — and that pattern could point to either condition, or both at once.

Here's the honest starting point: ADHD and autism are different conditions, they share several traits, and a child can absolutely have both. Until 2013 clinicians weren't even allowed to formally diagnose both together; that rule changed, and we now know the two frequently co-occur. This guide explains what separates them, where they overlap, and how assessment and support work in Singapore.

The Short Answer

ADHD (Attention-Deficit/Hyperactivity Disorder) is defined by inattention, hyperactivity and impulsivity. Autism (Autism Spectrum Disorder, ASD) is defined by differences in social communication alongside restricted, repetitive behaviours or intense focused interests. They overlap in areas like attention, sensory sensitivity and emotional regulation, which is why they're easy to confuse — and a substantial proportion of autistic children also meet the criteria for ADHD. A formal assessment by a developmental paediatrician, child psychiatrist or psychologist is the only reliable way to tell which applies to your child, or whether both do.

What ADHD Looks Like

ADHD centres on three core areas (a child may lean more toward one):

• Inattention — difficulty sustaining focus, easily distracted, careless mistakes, trouble finishing tasks, appears not to listen.
• Hyperactivity — restless, fidgety, can't stay seated, always "on the go".
• Impulsivity — acts without thinking, interrupts, struggles to wait their turn.

A child with ADHD usually *wants* to connect socially and broadly understands social rules — they just struggle to regulate attention and impulses well enough to follow through.

What Autism Looks Like

Autism centres on two core areas:

• Social communication differences — finds back-and-forth conversation, eye contact, reading tone or body language, or understanding unwritten social rules genuinely difficult (not just inconsistent).
• Restricted and repetitive patterns — intense focused interests, a strong need for routine and predictability, repetitive movements (e.g. hand-flapping), and sensory sensitivities (to sound, light, texture, food).

The key distinction: an autistic child's social difficulties come from a *different way of processing* social information, not from inattention or impulsivity.

Where They Overlap (and Why They Get Confused)

Both conditions can involve:

• Attention difficulties — an autistic child may seem inattentive because they're absorbed in an interest or overwhelmed by sensory input, which looks like ADHD inattention.
• Sensory sensitivity — common in both.
• Emotional regulation challenges — meltdowns, frustration, big reactions.
• Social difficulties — though for different underlying reasons (impulsivity in ADHD vs social-processing differences in autism).
• Trouble with transitions and organisation.

Because the *visible behaviours* overlap so much, two children behaving similarly in a classroom can have entirely different underlying profiles. That's exactly why a professional assessment matters — surface behaviour alone won't tell you.

Can a Child Have Both ADHD and Autism?

Yes. This is common, and it's now formally recognised. Before the American Psychiatric Association's DSM-5 diagnostic manual was published in 2013, clinicians were not permitted to diagnose ADHD and autism together; DSM-5 removed that restriction. Studies since have reported that a meaningful share of autistic children also meet the criteria for ADHD — estimates vary widely by study and population, so treat any single percentage with caution and ask your assessing clinician what they see in your child.

A child with both will show the social-communication and repetitive-behaviour profile of autism *plus* the inattention, hyperactivity or impulsivity of ADHD. Recognising both matters because the support strategies differ — and missing one means the child only gets half the help they need.

How Assessment Works in Singapore

A reliable diagnosis comes from a qualified professional — a developmental paediatrician, child psychiatrist, or psychologist — not from an online quiz. The main routes:

• Public route: Ask a GP at a polyclinic for a referral to the Department of Child Development (DCD) at KK Women's and Children's Hospital (KKH), the Child Development Unit (CDU) at National University Hospital (NUH), or the Child Guidance Clinic at the Institute of Mental Health (IMH). Subsidised, though waiting times for a subsidised assessment commonly run several months to over a year.
• Private route: A private developmental paediatrician, child psychiatrist or psychologist — usually faster, but a full private assessment can run from several hundred to a few thousand dollars.

Assessment usually involves a clinical interview, questionnaires completed by parents and teachers, observation, and sometimes cognitive or developmental testing across more than one session. For the detailed route-by-route cost breakdown and current fee ranges, see CareCompare's guide to ADHD assessment in Singapore.

What a Diagnosis Means for Support and Funding

Whatever the label, the practical question for most parents is: what help is available, and what does it cost?

• Early intervention (under 6): Children with developmental needs — including autism, ADHD-related delays, or both — can be referred to the government-subsidised Early Intervention Programme for Infants & Children (EIPIC), where fees are means-tested. See CareCompare's EIPIC guide for costs and how to apply.
• Therapy: Speech therapy, occupational therapy and behavioural support (such as ABA) are the common interventions. These are generally not covered by insurance — see Does Insurance Cover ABA Therapy in Singapore?
• School support: Both mainstream schools (with Allied Educators) and special education (SPED) schools provide support depending on the child's needs.

There's also one insurance timing point worth knowing — and it only applies *before* a diagnosis is recorded. If your child doesn't yet have a formal diagnosis on their medical records, it's worth understanding how an Integrated Shield Plan (ISP) works, because most insurers apply an exclusion to new applications once a developmental condition is recorded. This is never a reason to delay an assessment. If you want to understand the options, you can compare Integrated Shield Plans currently open to new applicants with CareCompare's tool.