ADHD and ADD – similarities and differences

Put simply, ADD is ADHD without the “H.” If you have an ADD diagnosis, you also have an ADHD diagnosis, but you do not show enough — or clear enough — hyperactivity and impulsivity symptoms to meet criteria for the combined presentation.

ADHD predominantly inattentive presentation (ADD)

ADD (Attention Deficit Disorder) is a variant of ADHD where challenges are mainly about attention and focus. You may still have some hyperactivity or impulsivity, but the biggest hurdles are starting, staying motivated, and maintaining concentration.

With ADD, long tasks or projects with many steps are often hard. You may lose focus, drift into your own thoughts, and find it difficult to follow instructions, keep up in conversations, or notice details.

Symptoms of inattention

If you have ADD and are over 17, you have at least five — and if 17 or younger, at least six — of these ADHD inattention symptoms. They must have lasted at least six months and make daily demands hard without support. You often…

• are inattentive to details or make careless mistakes in school, work, or other activities
• find it hard to sustain attention on tasks or play
• seem not to listen when spoken to directly
• do not follow instructions and fail to finish tasks (not due to defiance or lack of understanding)
• find it hard to organise activities and tasks
• avoid or dislike tasks requiring long mental effort (e.g., schoolwork or homework)
• often lose things needed for daily life (keys, homework, pens, books, tools)
• are easily distracted by external stimuli
• are often forgetful in daily routines

How ADD can affect daily life

Common challenges involve keeping the whole picture together, remembering details, and not losing the thread in tasks.

It can feel unfair to hear you should “try harder, listen better, or get more motivated.” You may spend far more energy than others on planning, organising, and finishing tasks — and feel exhausted after a “normal” day at school or work.

Many with ADD also struggle to judge time. You might miss meetings, arrive late, or overcompensate by always being very early.

Often you do not like tasks requiring persistence, and you spend a lot of time looking for misplaced items. Others may see you as distracted or forgetful unless you invest significant effort in staying organised, on time, responsive to emails, or remembering to eat.

How is ADD different from combined ADHD?

You have combined ADHD if, in addition to ADD symptoms, you have at least six (or five if over 17) of these hyperactivity and impulsivity symptoms for more than six months, with clear daily impact. You often…

• find it hard to sit still with hands or feet
• leave your seat in situations where you are expected to stay
• run around, climb, or move more than is considered appropriate (in teens and adults this can be inner restlessness)
• find it hard to play or engage in leisure activities quietly
• seem “on the go” or “driven by a motor”
• talk excessively
• blurt out answers before a question is finished
• struggle to wait your turn
• interrupt or intrude on others (e.g., jumping into conversations or activities)

How combined ADHD can feel

For combined ADHD, the challenge is often finding a “just right” balance. Inner restlessness may keep you in motion and make recovery hard, raising the risk of stress or burnout.

Because inattention is also present, you may struggle to start, get stuck, or delay tasks that feel hard or boring. Others might see you as rushed, stressed, or careless, without realising how much you fight for focus and against fatigue.

Hyperactivity and impulsivity can lead to talking a lot or saying things you later regret — sometimes without ill intent. Inattention can mean missing social cues and saying things that land awkwardly or at the wrong time.

Does it matter if I have ADHD or ADD?

In practice, the type rarely changes care. Assessment and treatment are fundamentally the same for combined ADHD and predominantly inattentive ADHD (ADD).

You can formally meet ADD criteria because you have enough inattention symptoms, yet still have some hyperactivity/impulsivity — just not enough for the combined presentation.

The line between ADHD and ADD over time

What an ADHD diagnosis means has shifted over decades. The boundary between ADHD and ADD has always been somewhat fluid.

In the current DSM (2013), we no longer talk about separate diagnoses but about ADHD presentations. ADHD can show up differently between people — and can change over a lifetime.

This aligns with research showing symptoms can vary within the same person over the years. Hyperactivity and impulsivity may lessen in adulthood without the diagnosis disappearing. Often hyperactivity “moves inside” and shows up as inner restlessness or worry rather than visible activity.

Want to know more about assessment, treatment, or coaching? Contact us and we will guide you.