Anxiety and ADHD co-occur at high rates — a large proportion of adults with ADHD also meet criteria for an anxiety disorder. They also look alike from outside: restlessness, poor concentration, difficulty sleeping, tasks not completed.
The mechanisms are entirely different, and so are the treatments.
Telling them apart
The concentration problem. In anxiety, attention is captured by worry — you can’t focus because something specific is occupying the channel. In ADHD, attention is unstable regardless of content, including on things you want to do and aren’t worried about.
The restlessness. ADHD restlessness is present from childhood, across all settings, and is often physical and non-anxious. Anxious restlessness is tied to threat and tends to fluctuate with it.
The timeline. ADHD is developmental — present from childhood, in multiple settings, even if it was missed. Anxiety disorders often have a discernible onset.
The sleep problem. Anxious insomnia is a mind that won’t stop worrying. ADHD sleep difficulty is more often a delayed body clock and difficulty disengaging generally.
The anxiety that ADHD causes
This is the crucial distinction and the one clinicians most often miss. A great deal of anxiety in adults with ADHD isn’t a separate disorder — it’s an accurate response to a life of missed deadlines, forgotten commitments and unpredictable performance.
If you’ve been late, lost things and let people down for twenty years, anticipatory dread about the next occasion isn’t a distorted cognition. It’s a reasonable forecast based on excellent evidence.
Treating that with cognitive work aimed at correcting a distorted belief won’t go well, because the belief isn’t distorted. Treating the ADHD frequently resolves it.
The stimulant question
Stimulant medication can increase anxiety, particularly early on or at too high a dose — it raises heart rate and can produce jitteriness, which for someone with panic is exactly the sensation they fear.
But the more common outcome in practice is the opposite: anxiety improves on treatment, because the underlying source of chaos reduces. The picture is genuinely mixed and it’s individual.
Practically: start low, go slow, watch for whether anxiety tracks the dose, and know that non-stimulant options exist. If panic disorder is active and untreated, many clinicians would treat that first.
Which to treat first
Generally: whichever is more impairing, and if the anxiety looks like a consequence of ADHD-driven chaos, treat the ADHD.
Where both are significant, CBT for anxiety needs adapting —the homework is the treatment, and homework is structurally harder with ADHD. A clinician who understands that will shrink it, add external structure, and treat a missed worksheet as a design problem rather than a motivation one.