Restlessness. Difficulty concentrating. Racing thoughts. Sleep problems. These symptoms belong to both ADHD and generalised anxiety disorder, which is why so many adults spend years being treated for the wrong one. Research shows that 47 to 53% of adults with ADHD also meet criteria for an anxiety disorder, making this one of the most common diagnostic overlaps your GP encounters.
Getting the diagnosis right matters because treating ADHD with anxiolytic strategies alone does not fix executive function deficits, and treating anxiety with stimulants alone risks making the anxiety worse.
In this article
- Symptoms that overlap between ADHD and anxiety
- Why the overlap causes misdiagnosis
- How GPs tell them apart: the DSM-5 approach
- When it is both: comorbidity rates in adults
- Why treating the wrong one makes the other worse
- How a structured GP assessment differentiates them
- Frequently asked questions
Symptoms that overlap between ADHD and anxiety
ADHD and generalised anxiety disorder (GAD) share a cluster of symptoms that look nearly identical on the surface. Understanding what drives each symptom is the key to distinguishing them.
Restlessness. In ADHD, restlessness stems from a need for stimulation. The brain is under-aroused and seeks movement or novelty. In anxiety, restlessness is driven by worry. The body is in a heightened alert state because the mind is anticipating threat.
Difficulty concentrating. ADHD concentration problems are consistent across situations, including enjoyable ones. The brain struggles to sustain attention on anything that is not immediately rewarding. Anxiety-driven concentration problems are selective: focus drops when worry intrudes, but returns when the source of worry resolves.
Sleep difficulties. Adults with ADHD often have delayed sleep onset because the brain does not “switch off” easily. Adults with anxiety have sleep-onset insomnia too, but it is driven by rumination and worry about specific things. ADHD sleep difficulty tends to feel like a busy, non-directional mind. Anxiety sleep difficulty has a theme.
Irritability. Both conditions produce irritability, but the triggers differ. ADHD irritability often follows frustration with executive function failures (losing things, forgetting tasks, running late). Anxiety irritability follows feeling overwhelmed by perceived demands or threats.
Avoidance. Adults with ADHD avoid tasks because they feel boring or overwhelming (executive function avoidance). Adults with anxiety avoid situations because they fear a negative outcome.
Why the overlap causes misdiagnosis
Standard screening tools struggle to separate ADHD from anxiety. Research has shown that commonly used rating scales have limited sensitivity and specificity for differentiating ADHD from anxiety in adults. A GP using only a symptom checklist without exploring the context behind each symptom will find both conditions scoring high.
The misdiagnosis pattern typically runs one way: ADHD gets missed, and anxiety gets diagnosed. This happens because anxiety is more familiar to most clinicians, the patient presents with worry and tension as the chief complaint (masking the ADHD underneath), and standard depression and anxiety screeners pick up the surface symptoms without identifying their root cause.
Women are disproportionately affected by this pattern. The inattentive presentation of ADHD common in women looks like anxiety to clinicians unfamiliar with adult ADHD presentations.
How GPs tell them apart: the DSM-5 approach
The DSM-5 provides differential diagnosis criteria that help GPs distinguish ADHD from anxiety disorder. Your GP will look at several distinguishing features during a thorough assessment.
Age of onset. ADHD symptoms must be present before age 12, even if they were not recognised at the time. Anxiety disorders can develop at any age. If concentration problems only started in your 30s with no childhood history, ADHD is less likely to be the primary cause.
Pervasiveness. ADHD symptoms appear across all settings: work, home, relationships, hobbies. Anxiety symptoms are often situation-dependent or triggered by specific concerns (financial stress, health worries, social evaluation).
Nature of the thought pattern. ADHD produces scattered, jumping thoughts without a consistent theme. Anxiety produces repetitive, theme-focused worry. Your GP will ask what your mind does when you cannot concentrate: does it jump between random topics, or does it circle back to the same worry?
Response to novelty. ADHD brains light up with novel, stimulating tasks. If you can hyperfocus on something new and interesting but cannot sustain attention on routine tasks, that pattern points to ADHD. Anxiety does not produce this differential response to novelty.
Childhood history. Your GP will ask about primary school years: report card comments, organisational difficulties, forgetting homework, daydreaming in class. These patterns pre-date anxiety in most cases and point towards ADHD as the foundational condition.
When it is both: comorbidity rates in adults
ADHD and anxiety are not always an either-or diagnosis. The National Comorbidity Survey Replication found that 47% of adults with ADHD also meet criteria for an anxiety disorder. Other studies place this figure between 25% and 53%, depending on the population studied and the assessment method used.
Generalised anxiety disorder is the most common anxiety comorbidity, appearing in 25 to 30% of adults with ADHD. Social anxiety disorder and specific phobias also occur at higher rates than in the general population.
When both conditions are present, the clinical picture is more complex. Research shows that adults with comorbid ADHD and anxiety experience higher disease burden, longer illness duration, and reduced quality of life compared to adults with either condition alone. They also have higher rates of suicidal ideation and more difficulty with anger regulation.
This is why accurate assessment matters: treating only the anxiety in someone with comorbid ADHD leaves half the problem unaddressed.
Why treating the wrong one makes the other worse
Treating anxiety when ADHD is the primary condition often backfires. SSRIs and other anxiolytics do not address executive function deficits. The patient continues to miss deadlines, lose belongings, and struggle with organisation. These ongoing failures generate more anxiety, creating a cycle that no amount of anti-anxiety medication will break.
Conversely, prescribing stimulant medication to someone whose primary condition is anxiety (without ADHD) increases sympathetic nervous system activation. Stimulants raise heart rate, increase alertness, and amplify the physiological symptoms of anxiety. The patient feels worse, not better.
When both conditions are present, Australian clinical guidelines recommend treating the most impairing condition first. In many cases, treating ADHD first with stimulant medication reduces a significant portion of the anxiety, because the anxiety was secondary to executive function failures. If anxiety persists after ADHD is adequately treated, it can then be addressed with appropriate therapy or medication.
Your GP will monitor for both conditions throughout treatment and adjust the plan based on your response. This is part of the ongoing medication management process described in our post on GP ADHD prescribing in Australia.
How a structured GP assessment differentiates them
A thorough ADHD assessment does not rely on a single questionnaire. GPs trained in ADHD assessment use a structured approach that specifically addresses the ADHD-anxiety overlap.
The assessment typically includes the ASRS v1.1 (Adult ADHD Self-Report Scale) as a screening tool, followed by a clinical interview exploring childhood behaviour, developmental history, symptom chronology, and functional impact across multiple life domains. Your GP will also gather collateral information from someone who knew you as a child (a parent, sibling, or school reports) to establish whether symptoms were present before age 12.
Critically, your GP will ask about the relationship between your concentration problems and your worry. Do you worry because you cannot concentrate (suggesting ADHD driving secondary anxiety)? Or can you not concentrate because you are worrying (suggesting anxiety as the primary condition)?
The pre-consultation preparation used by specialist GPs collects much of this information before the appointment, so the consultation time focuses on clinical judgement rather than form-filling. If you are wondering whether your symptoms are ADHD, anxiety, or both, the ADHD assessment is a useful starting point.
Frequently asked questions
Can you have both ADHD and anxiety at the same time?
Yes. Research shows that 47 to 53% of adults with ADHD also meet diagnostic criteria for an anxiety disorder. Generalised anxiety disorder is the most common overlap, affecting 25 to 30% of adults with ADHD. Having both conditions is the rule rather than the exception, which is why a thorough assessment that evaluates both is important.
Will ADHD medication make my anxiety worse?
It depends on the source of your anxiety. If your anxiety is secondary to ADHD (caused by executive function failures like missing deadlines and forgetting things), stimulant medication often reduces anxiety by addressing the root cause. If you have a primary anxiety disorder alongside ADHD, your GP will monitor closely and may start with a lower stimulant dose or add anxiety-specific treatment. See our ADHD assessment page for more on how GPs manage this.
How do I know if my concentration problems are ADHD or anxiety?
Ask yourself two questions. First, have you had concentration problems since childhood (before age 12), or did they start later? ADHD is a lifelong condition present from childhood, although in some people symptoms improve dramatically by young adulthood. Second, does your mind jump between random topics, or does it circle back to specific worries? ADHD produces scattered, theme-free distraction. Anxiety produces focused, repetitive worry. A GP trained in ADHD assessment will explore both patterns.
Can a GP diagnose both ADHD and anxiety?
Yes. In Queensland, specialist GPs with RACGP or ACRRM fellowship can diagnose and treat both ADHD and anxiety disorders. A structured assessment explores both conditions simultaneously. If both are present, your GP will develop a treatment plan that addresses both, typically starting with the more impairing condition first.
Why was I diagnosed with anxiety but not ADHD?
Anxiety is more commonly recognised in primary care than ADHD, particularly in women with the inattentive ADHD presentation. Standard anxiety screeners pick up surface symptoms (restlessness, poor concentration, sleep problems) without distinguishing their cause. If anxiety treatment has not resolved your concentration and organisational difficulties, an ADHD screening is a worthwhile next step.
ADHD and anxiety are among the most commonly confused conditions in adult mental health. The symptom overlap is real, the comorbidity rate is high, and getting the diagnosis right changes the entire treatment trajectory. If you have been treated for anxiety without improvement in your concentration, organisation, or task completion, an ADHD assessment is worth pursuing.
Queensland specialist GPs can assess for both conditions. Start with our ADHD assessment to see if a full assessment is appropriate for you.
General health information
This article is general health information only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always speak with a qualified health professional before making any changes to your medication or treatment plan.
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