ADHD symptoms in adults

The three presentations of ADHD

ADHD is diagnosed using the DSM-5-TR, which lists nine inattentive symptoms and nine hyperactive-impulsive symptoms. Adults aged 17 and over need at least five from a group, present for six months or more, to meet criteria for that presentation.

Signs of inattention

• Making careless mistakes at work or in paperwork, even when you know better.
• Struggling to hold attention on long tasks, meetings, reading or conversations.
• Seeming not to listen when spoken to directly; your mind is elsewhere.
• Starting tasks but not finishing them, especially bills, forms and admin.
• Difficulty organising: messy systems, missed deadlines, poor time estimates.
• Avoiding or dreading tasks that need sustained mental effort.
• Losing keys, phones, wallets, documents, and the time spent looking for them.
• Being easily distracted by noise, notifications or your own thoughts.
• Forgetting appointments, calls to return, and errands.

Many adults describe this as "I can focus intensely on things I love and not at all on things I must do". Hyperfocus is real and common in ADHD, but it is not the same as reliable attention.

Signs of hyperactivity and impulsivity

• Fidgeting, tapping, shifting in your seat, or needing to move during meetings.
• Feeling unable to sit through a film, a long dinner or a quiet afternoon.
• An inner sense of being "driven by a motor", even when outwardly still.
• Talking a lot, quickly, or finishing other people's sentences.
• Interrupting, blurting out answers, jumping into others' conversations.
• Difficulty waiting: in queues, in traffic, for a reply.
• Impulsive spending, eating, decisions or job changes.

In adults, the visible bouncing of childhood often fades. What remains is restlessness, impatience and a habit of doing several things at once to feel occupied.

How ADHD symptoms differ between adults and children

ADHD is the same condition across the lifespan, but its shape changes. Children are more likely to run, climb and call out. Adults have usually learned to sit still, so the hyperactivity moves inward. Inattention, on the other hand, tends to persist or become more obvious as life gets more complex: managing a household, a career, finances and relationships demands exactly the skills ADHD makes hard.

Adults also carry the consequences. Years of missed deadlines, lost jobs, strained relationships and being called lazy or careless can leave a residue of shame and low self-esteem that is not itself a symptom of ADHD but is very often part of the picture.

Anxiety, depression and other conditions that co-occur

Around half of adults with ADHD have at least one other mental health condition. Anxiety and depression are the most common. Sometimes they are separate conditions. Often they are a response to living with undiagnosed ADHD: constant worry about what you have forgotten, and low mood from repeated setbacks.

This matters for assessment. Anxiety can cause poor concentration, and depression can cause forgetfulness and low motivation, so a clinician needs to work out what is driving what. The AADPA guideline recommends screening for co-occurring conditions as part of every ADHD assessment. Sleep disorders, autism (see AuDHD), learning differences and thyroid problems are among the other things a thorough assessment considers.

When to get assessed

Consider an assessment if several of the signs above have been present since childhood, show up in more than one area of your life, and cause real difficulty rather than occasional annoyance. Everyone loses their keys sometimes. ADHD is when the pattern is persistent, pervasive and costly.

A free screener is a reasonable first step. The WHO ASRS ADHD test takes a few minutes and tells you whether a full assessment is worth pursuing. It does not diagnose. Women often score differently and may present in ways screeners miss; see ADHD in women. For what happens next, read how ADHD assessment works.

What Inner Help does

Inner Help provides online ADHD assessment and care across Australia. Assessments are done by ADHD-trained GPs with a psychiatrist medical director overseeing and reviewing files where a state requires it. Assessment, diagnosis and prescribing are separate decisions.

ADHD assessment with Inner Help opens state by state in 2026: GP-led with psychiatrist oversight, workup at a clinic near you, price and process published in full before it opens. Join the waitlist. You do not need a diagnosis to start therapy now.

Frequently asked questions