Patient Education · Adult ADHD
Is it ADHD, anxiety, depression, or something else?
Difficulty concentrating is one of the least specific symptoms in medicine. It is where anxiety, low mood, poor sleep, alcohol, thyroid disease, grief, burnout and ADHD all eventually show themselves. Deciding between them is not a matter of counting symptoms; it is a matter of examining the pattern across a lifetime and across settings.
A Shared Symptom
Attention is where
many problems surface
Concentration depends on sleep, mood, anxiety level, motivation, physical health, substances and the demands of the environment. Disturb any of these and attention suffers. That is why an online checklist asking whether you lose focus, misplace things or leave tasks unfinished will return a positive result for a very large number of people who do not have ADHD.
It is also why the same checklist misses people who do. Someone who has organised their entire life around compensating may answer honestly and score low, while paying an enormous private cost to do so.
The Timeline
Trait or episode:
the question that separates them
ADHD is a neurodevelopmental condition. The diagnostic criteria in DSM-5-TR require several symptoms to have been present before the age of twelve, symptoms in at least two settings such as home and work or school, and clear interference with functioning. ICD-11 describes a similar clinical picture but words it differently: symptoms outside the range expected for the person’s age, evident across multiple situations, beginning during the developmental period and typically by early to mid childhood. ICD-11 sets no symptom counts and no severity specifiers.
Anxiety and depression, by contrast, usually have a beginning. There was a period before, a change, and often a plausible trigger. When someone can point to a year when concentration was fine and describe what shifted, that is a meaningful piece of evidence. When someone describes the same difficulty at seven, seventeen and thirty-seven, that is a different piece of evidence.
School reports, a parent or older sibling’s recollection, and old employer feedback are genuinely useful here. Memory of childhood is imperfect for everyone, and a diagnosis resting on adult self-report alone is on weaker ground than one supported by an independent account.
Patterns
The same complaint,
with different fingerprints
| Condition | How attention typically fails | Distinguishing features |
|---|---|---|
| ADHD | Lifelong difficulty starting, sustaining and switching tasks; better with novelty, urgency or interest | Present since childhood, across settings, with restlessness or impulsivity in many but not all |
| Anxiety disorder | Attention captured by worry or by scanning for threat; mind goes blank under pressure | Physical arousal, avoidance, anticipatory dread; often worse in specific feared situations |
| Depression | Slowed thinking, loss of interest and drive, indecision | Episodic; low mood, sleep and appetite change, hopelessness, withdrawal |
| Sleep disorder | Daytime sleepiness, lapses, irritability | Snoring, witnessed pauses in breathing, unrefreshing sleep, insufficient sleep opportunity |
| Substance use | Variable, often worst on days after use or during withdrawal | Clear relation to use; alcohol, cannabis and heavy caffeine or nicotine all matter |
| Physical illness | Fatigue-linked, with slowed processing | Thyroid disorder, anaemia and other conditions found on history and appropriate tests |
The table is a way of organising a conversation, not a self-diagnosis tool. In real consultations two of these rows are often true at the same time.
When Both Are True
Coexistence is common,
and it changes the sequence
Anxiety and depression are frequent companions of ADHD rather than alternatives to it. Years of missed deadlines, lost items, unfinished degrees and being described as careless produce anxiety and low self-esteem quite reasonably. So a common answer to the question in this article’s title is: both. In many people the ADHD is the older of the two and the anxiety or low mood developed alongside years of unrecognised difficulty, though the relationship runs in both directions and the sequence has to be established case by case.
What matters clinically is sequence. A current moderate or severe depressive episode, untreated obstructive sleep apnoea, or hazardous drinking will each undermine an ADHD treatment plan and will also distort any assessment done during them. It is usually right to name all the problems at once and then be explicit about which is being treated first and why.
What Assessment Involves
A questionnaire is a prompt,
not a diagnosis
NICE is unambiguous that ADHD should only be diagnosed by a specialist psychiatrist, paediatrician or other appropriately qualified professional with training and expertise in diagnosing it, on the basis of a full clinical and psychosocial assessment, a full developmental and psychiatric history, and observer reports and mental state assessment. It states equally clearly that a diagnosis should not be made solely on the basis of rating scale or observational data.
Rating scales still have a job. They structure enquiry, they make it harder to forget a domain, and they give a rough baseline to compare against later. They cannot establish onset, they cannot establish impairment, and they cannot exclude the conditions that imitate ADHD.
Computerised attention tests measure performance on a specific task in a specific room on a specific day. A normal result does not exclude ADHD, and an abnormal result does not establish it. Any clinic presenting a machine result as the diagnosis is overselling what the technology can do.
Common Beliefs
Four beliefs
worth examining
When to Seek Assessment
The threshold is impairment,
not curiosity
A formal assessment is worth arranging when the difficulty is persistent, present in more than one part of life, and costing you something concrete: repeated job changes, an unfinished course, unpaid bills or disordered finances, strained relationships, or a child struggling at school despite adequate teaching and support.
It is also worth arranging when treatment for something else has not worked as expected. Antidepressants that lift mood but leave organisation untouched, or anxiety treatment that helps the worry but not the chaos, sometimes point towards an underlying pattern that was never assessed.
Care With Dr. Shaurya Garg
If this article
sounds familiar
If the pattern here sounds familiar, this page sets out what a clinician-led adult ADHD assessment involves, and this article covers ADHD in adults whose ability has masked it for years.
If anxiety or low mood seems the closer fit, see stress or an anxiety disorder and low mood or depression. Dr Shaurya Garg offers consultations online across India and in person in New Delhi.
Sources & Further Reading
· NICE NG87: attention deficit hyperactivity disorder, diagnosis and management
· American Psychiatric Association: DSM-5-TR, the diagnostic criteria used for ADHD
· World Health Organization, ICD-11, code 6A05: attention deficit hyperactivity disorder
· NICE HTG729, formerly DG60: digital technologies for assessing ADHD
Sources are provided for education and were reviewed on 28 July 2026. They do not replace individual clinical assessment.
Common Questions
Telling them apart,
answered plainly
Can anxiety cause the same symptoms as ADHD?
Yes. Anxiety fragments attention, interferes with working memory and can cause restlessness. The usual difference is timing: anxiety-driven attention problems tend to have a beginning and to fluctuate with the anxiety, while ADHD is a lifelong pattern present across settings.
Can an online ADHD test diagnose me?
No. Rating scales can prompt a useful conversation and provide a baseline, but NICE states that a diagnosis should not be made on rating scale or observational data alone. Diagnosis requires a specialist clinical and developmental assessment.
Is it possible to have ADHD and depression together?
Yes, and it is common. Long-standing ADHD often produces low self-esteem, anxiety and depression. The assessment should name every condition present and be explicit about which is being treated first.
My concentration only became a problem in my thirties. Is that adult-onset ADHD?
Genuinely new attention problems in adulthood usually have another cause, such as depression, a sleep disorder, alcohol, a medical condition or medication. That deserves investigation. ADHD symptoms should be traceable back to childhood.
Do computerised attention tests prove ADHD?
No. They measure performance on one task at one moment. A normal result does not exclude ADHD and an abnormal result does not establish it. They can support a clinical assessment but cannot replace it.