Content reviewed by

Psychologist & Behaviour Analyst
ADHD Symptoms: What you need to know
A comprehensive ADHD assessment considers two core symptom groups: inattention and hyperactivity–impulsivity.
In adults, these may appear as difficulties with concentration, forgetfulness, inner restlessness, time management and acting before fully considering the consequences.
What matters is a persistent pattern. The features should appear across multiple settings and have a noticeable impact on daily functioning.
Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental condition. Its features begin in childhood and may continue into adulthood. The New Zealand Attention Deficit Hyperactivity Disorder Clinical Principles Framework (NZ Framework) describes inattentive features such as distractibility, forgetfulness, organisational difficulties and difficulty sustaining effort.
Hyperactivity–impulsivity may include restlessness, excessive activity, talkativeness and acting without sufficient forethought. In adults, these features may be less visible, change in form with age and become more noticeable as responsibilities increase.
The two core symptom groups are inattention and hyperactivity–impulsivity. They are separated below only for readability.
Inattention
Inattention may involve difficulty directing and sustaining effort where it is needed most, especially during repetitive or mentally demanding tasks. A person may work for hours on an engaging project yet postpone a short form due that day. It may also appear as losing track of a conversation, forgetting to reply or overlooking details.
Hyperactivity
In adults, hyperactivity may appear as internal restlessness rather than obvious movement. A person may remain seated while changing position or handling an object. The Centers for Disease Control and Prevention (CDC) lists internal restlessness and fidgeting as possible adult expressions. Restlessness alone does not confirm ADHD; context, duration and other features also matter.
Impulsivity
Impulsivity may involve responding or agreeing before thinking through likely consequences. A person may interrupt because they fear losing a thought or accept a responsibility without checking whether it overlaps with existing commitments. It may also look like sudden, intense emotional reactions that take longer to settle.
Work and study
ADHD-related difficulties may affect education and employment even when ability and motivation remain strong. Someone may complete a complex part of a project but stall on routine final steps while smaller requests take over the day. Others may misread this inconsistency as a lack of effort. Similar difficulties may emerge in higher education when long-term work requires less external structure. Assessment considers repeated functional impact, not whether a person appears capable.
Difficulty is not always a lack of motivation
An interesting or urgent task may be easier to begin
Routine final steps may require more external structure
The final result may not show how much effort was needed to achieve it
Relationships and communication
Inattention, forgetfulness, talkativeness and impulsivity may affect communication. A person may forget to reply to a message or enter an agreed plan in a calendar. During conversation, they may lose track, respond to an earlier point, interrupt or change the subject. To them, this may reflect attention or impulse-control difficulties; to the other person, it may feel dismissive. Repeated patterns can create tension. Understanding the reason may clarify intention but does not remove impact.
Intention and impact may differ
A person may genuinely value a relationship and still forget an agreement
The National Institute for Health and Care Excellence (NICE) recommends explaining how ADHD may affect relationships and everyday functioning
Clear, direct communication may help reduce misunderstandings
Time, finances and administration
ADHD features may affect organisation, time management and financial administration. A person may plan to pay a bill after work but miss the moment to act. The 2022 Australian ADHD guideline notes that forgetfulness and time-management difficulties may interfere with repeat prescriptions, collecting medication or follow-up appointments. Financial effects may include impulsive purchases, missed payments or hard-to-cancel subscriptions. Assessment considers the pattern, not any single example.
Home
Household tasks often require a sequence of actions. Laundry may stop partway through if attention shifts. Meal planning likewise involves choosing a meal, checking supplies, buying ingredients and starting at the right time. These examples show how attention, planning and self-regulation may affect daily life; they are not additional diagnostic symptoms.
Area
Key Question
Work or study
Do difficulties with deadlines, priorities or task/project completion recur?
Relationships
Do forgetfulness, interrupting or losing track affect relationships?
Time and finances
Is there a persistent pattern of postponement, impulsive spending or unfinished administration?
Home
How consistently are everyday responsibilities completed?
Overall pattern
How long have the difficulties been present, and in how many important settings do they occur?
Executive functioning and emotional regulation
Executive functioning supports starting actions, holding goals in mind, setting priorities and shifting tasks. Difficulties may include starting late, losing a sequence or underestimating time. They matter to the overall picture but are not a separate core symptom group or ADHD presentation. The NZ Framework notes emotional regulation difficulties are common but not required for diagnosis.
Emotional Regulation
Intense emotions may contribute to conflict or lower self-esteem
Decision-making may be harder during emotional situations
Recovery after stress may take longer
Attention, memory, organisation and inner restlessness difficulties are not specific to ADHD. Assessment considers when they began and whether another condition could better explain them. Possibilities include sleep problems, anxiety, depression, trauma, medication effects, thyroid conditions, anaemia, hearing or vision problems, brain injury, hormonal changes or other neurological conditions. More than one condition may be present.
Assessment considers functional impairment: whether difficulties noticeably affect psychological, social, educational or occupational life. A clinician also looks for features that occur often, are present in two or more important settings and have persisted over time. Evidence of relevant childhood features forms part of the overall assessment.
The NZ Framework describes a comprehensive assessment using a detailed clinical interview and information from several sources. It considers developmental history, current symptoms, functional impact, co-occurring conditions and alternative explanations. Rating scales add information but cannot establish a diagnosis alone. The Canadian ADHD Resource Alliance (CADDRA) compares a scale to a thermometer: it can flag a concern but not identify its cause. Clinical judgement and the lifelong pattern are required.
A brief screener may suggest whether further assessment could be useful, but it cannot confirm or rule out ADHD.
