ADHD in Kids: Signs, Symptoms, and What Parents Need to Know

So you’ve started to wonder whether what you’re seeing in your child is
ordinary kid stuff — or something more. We sit with that question a lot.
Most weeks, parents come into our Toronto practice somewhere between worried
and unsure: they’ve read conflicting things online, a teacher has flagged a
concern, or a pattern at home just isn’t adding up. If that’s you, you’re in
the right place — and you’re not overreacting by asking. We offer
ADHD therapy and counseling
for families navigating exactly this.

Here’s the honest part: a lot of what looks like ADHD is also just being a
kid. Children are meant to be active, distractible, and impulsive at times —
especially at certain ages. The difference with ADHD isn’t any single
behavior; it’s the pattern. The signs show up consistently, in more than one
setting, for at least six months, with several present before age 12 — and
they get in the way of everyday life in a way ordinary high energy doesn’t.
An energetic kid can usually rein it in when it matters. A child with ADHD
often can’t, no matter how hard they try. This guide walks through what ADHD
actually looks like in children at different ages, how it can show up
differently in girls, what tends to travel alongside it, and what a real
assessment involves.

Key Takeaways

• ADHD is one of the most common neurodevelopmental conditions in children
  and adults.
• It’s shaped by a mix of genetic, neurological, and environmental factors —
  not by parenting or screen time alone.
• ADHD often presents differently in girls than in boys, which is part of
  why girls are diagnosed later.
• A formal diagnosis comes from a structured assessment by a qualified
  professional — not from a single questionnaire or a hunch.

So, What Is ADHD, Really?

ADHD stands for Attention-Deficit/Hyperactivity Disorder, and it’s the most
common neurodevelopmental condition in children.
CADDAC (the Center for ADHD
Awareness, Canada) estimates it affects roughly 5–7% of children in Canada.
It’s also strongly heritable.

Research published in Nature Reviews Disease Primers describes ADHD as
having a largely genetic basis involving both common and rare genetic
variants. The
Canadian Pediatric Society
frames it as a chronic neurodevelopmental disorder with genetic,
neurological, and environmental contributors — drawing its definition from
the DSM-5: a persistent pattern of inattention and/or
hyperactivity-impulsivity that interferes with development and gets in the
way of everyday functioning.

What Does ADHD Look Like in Children?

At its core, ADHD affects how a child regulates attention, impulses, and
energy. Every child is distractible or restless sometimes, but children with
ADHD experience this more intensely and more persistently, in ways that
reach into home, school, and friendships. Noticing the pattern early matters
because the right support genuinely changes how a child experiences their
day.

Does ADHD Look Different at Different Ages?

ADHD doesn’t look the same at five as it does at fifteen. As kids grow, the
demands on their attention and self-regulation shift — and so do the signs.

Age Group	Common Signs	What Parents & Teachers Often Notice
Ages 3–5	Hyperactivity, impulsiveness, big emotional reactions, sleep struggles	Frequent meltdowns, constant movement, difficulty sitting still, lots of talking, trouble with routines and transitions
Ages 6–12	Inattention, forgetfulness, impulsivity, emotional frustration	Losing homework, careless mistakes, zoning out in class, interrupting, difficulty following instructions, friction with peers
Ages 13–17	Procrastination, disorganization, emotional dysregulation, time blindness	Missed deadlines, chronic lateness, messy systems, unstable friendships, underperforming despite clear ability

How Do I Know If My Daughter Has ADHD? Is It Different for Girls?

This is one of the most common — and most missed — questions we hear.
Pulling together the research and our own clinical experience, here’s what
tends to be true:

• ADHD in girls and women
  often stays under the radar until adolescence or even adulthood.
• In girls, ADHD is frequently mistaken for anxiety or depression.
• Many describe daydreaming and “tuning out” rather than visible
  hyperactivity.
• Girls with ADHD often turn the struggle inward — self-blame, low
  self-esteem, and crying easily.
• Staying organized and meeting deadlines can be a persistent challenge.
• Perfectionism and people-pleasing can quietly mask the underlying
  difficulty.
• Anxiety and depression frequently co-occur.
• Friendships and later relationships can be hard to maintain.

None of this means girls have a “milder” version of ADHD. It means it’s
quieter — and quiet is easy to overlook. ADHD in Girls vs. Boys: A
Side-by-Side Look

Category	Boys with ADHD	Girls with ADHD
Most Common Presentation	More often hyperactive or combined	More often inattentive
How It Shows Up	Louder, physical, disruptive	Quieter, internalized, easy to overlook
Hyperactivity	Running, climbing, constant motion, interrupting	Quiet fidgeting, nail-biting, hair-twirling, inner restlessness
Attention	Visibly struggles to stay seated or focused	Daydreaming, drifting off, missing details, or assignments
Emotional Response	Outward frustration and anger	Anxiety, sensitivity, low self-esteem, and overthinking
Social Side	Trouble following rules or curbing impulses	Harder to read social cues or hold friendships
At School	Behaviour gets noticed early	Works hard to mask it, may still underperform
Diagnosis Timing	Usually identified earlier (more disruptive)	Often, later symptoms read as “shy” or “quiet.”
Why It Gets Missed	Behaviour pulls adult attention quickly	Mistaken for personality, stress, or daydreaming

Can My Child Have Autism or Dyslexia Alongside ADHD?

Often, yes — ADHD rarely travels alone.

• Autism and ADHD frequently overlap. One 2024 study found about a third of
  autistic children also met the criteria for ADHD, though estimates vary
  widely across studies.
• ADHD and dyslexia overlap too — commonly cited figures put the
  co-occurrence at roughly 25–40%. A 2024 University of Edinburgh study
  helped explain why, identifying scores of genes shared between the two.
• In our own Toronto practice, most children referred for an
  ADHD assessment
  turn out to have at least one other condition in the picture.

The conditions that most often show up alongside ADHD include:

• Learning differences — particularly dyslexia and dyscalculia
• Autism Spectrum Disorder (ASD)
• Oppositional Defiant Disorder (ODD) — a pattern of irritable mood and
  defiant behaviour

Here’s what my ADHD clients have taught me
about how these pieces fit together in real life.

How Is ADHD in Kids Supported?

Support tends to work best as a combination rather than a single fix:

• Behavioural therapy
• Parent coaching
• School accommodations
• Medication, when recommended by a physician
• Everyday structure — predictable routines, movement, and clear
  expectations

Kids with ADHD do best with consistency, patience, and feedback that catches
them doing well rather than only naming what went wrong.

What Should Ontario Parents Know About Getting a Diagnosis?

A few practical things if you’re pursuing a formal ADHD diagnosis for your
child in Ontario:

• A formal diagnosis needs to come from a qualified professional — in
  Ontario, that means a physician or a registered psychologist.
• A written psychological assessment report is usually what schools rely on
  to put accommodations in place, such as an Individual Education Plan (IEP)
  under the Education Act.
• Ask for that written report — it’s the document that opens the door to
  school support.

How Do You Book an ADHD Assessment in Toronto? What’s the Process?

Stage	What Happens
Initial Booking	You can contact So You Need Therapy directly — no doctor’s referral is required to get started.
Insurance & OHIP	OHIP generally doesn’t cover psychological assessments, but many extended health plans cover part of the cost. It’s worth checking your benefits early.
Parent Intake	A conversation about your child’s developmental history, behaviour patterns, school concerns, emotional world, and daily routines.
Rating Scales	Parents and teachers complete standardized questionnaires covering attention, impulsivity, hyperactivity, and emotional regulation.
Clinical Interview & Testing	Depending on the referral, your child may complete testing that looks at executive functioning, memory, processing speed, and attention.
Screening for Related Conditions	The assessment also looks for anxiety, learning differences, and other conditions that often occur alongside ADHD.
Feedback & Report	You receive a written report explaining the findings and providing clear recommendations for school and support.
Timeline	From start to finish, the process usually takes 2–4 appointments over a few weeks.

So, What’s the Takeaway?

ADHD doesn’t always look the way people expect. Some kids are visibly on the
move; others are quietly drifting, working twice as hard just to keep up.
The most useful thing any parent or teacher can do is watch for consistent
patterns rather than one-off moments.

Early recognition, steady support, and a proper assessment can change how a
child experiences school, friendships, and themselves. If your child is
struggling and you’re not sure what’s going on, that’s exactly the kind of
question we can help you think through.
So You Need Therapy works with
neurodivergent kids, teens, and families across Toronto. Send us a message
when you’re ready.