ADHD and Anxiety: Understanding the Overlap

ADHD and anxiety disorders are among the most common mental health conditions in adults, and they frequently occur together. Research suggests that up to 50% of adults with ADHD also have an anxiety disorder. Understanding the relationship between them is essential for accurate diagnosis and effective treatment.

How ADHD causes anxiety

ADHD itself does not directly cause anxiety, but the lived experience of ADHD often does. Chronic difficulties with organisation, time management, and follow-through lead to repeated failures, missed deadlines, and relationship difficulties. Over time, this creates a pattern of anticipatory anxiety -- a constant low-level fear of what will go wrong next.

Rejection sensitive dysphoria (RSD), which is common in ADHD, can also manifest as intense anxiety in social situations. The fear of saying the wrong thing, being judged, or disappointing others can lead to significant social anxiety that is actually rooted in ADHD rather than a primary anxiety disorder.

How anxiety affects ADHD

Anxiety can make ADHD symptoms worse. The cognitive load of anxious rumination reduces the mental bandwidth available for attention and executive function. Avoidance behaviours driven by anxiety can compound the disorganisation and procrastination already present in ADHD. The result is a cycle where ADHD creates anxiety, and anxiety makes ADHD worse.

Which came first? The clinical importance of this question

This is a clinically important question that affects treatment planning. In some cases, anxiety is a secondary consequence of untreated ADHD. In these cases, treating the ADHD often reduces the anxiety significantly -- sometimes dramatically. In other cases, the anxiety disorder is primary and independent of the ADHD. In these cases, treating the ADHD alone will not resolve the anxiety.

A comprehensive ADHD assessment should explore this question carefully. Key indicators that anxiety is secondary to ADHD include anxiety that is primarily about performance, deadlines, and social situations related to ADHD difficulties, anxiety that began or worsened as the demands of adult life increased, and anxiety that is driven by specific ADHD-related fears (forgetting things, being late, making mistakes).

Distinguishing ADHD from anxiety

ADHD and anxiety can look similar on the surface. Both can cause difficulty concentrating, restlessness, and sleep problems. The key distinctions are:

Treatment considerations

When ADHD and anxiety co-occur, treatment typically involves addressing both conditions. The sequence matters:

If the anxiety is secondary to ADHD, treating the ADHD first is often the most effective approach. As ADHD symptoms improve, the anxiety often reduces without specific treatment.

If the anxiety is primary or severe, it may need to be addressed alongside or before ADHD treatment. Stimulant medication for ADHD can sometimes increase anxiety in the short term, though this often settles with dose adjustment. Non-stimulant options such as atomoxetine may be preferred in some cases.

Psychological support, particularly CBT, is effective for both conditions. CBT for ADHD addresses the thought patterns and behaviours that maintain ADHD-related difficulties, while CBT for anxiety addresses worry and avoidance.

The importance of a comprehensive assessment

Because ADHD and anxiety overlap so significantly, a comprehensive assessment is essential. An assessment that only screens for one condition risks missing the other, leading to incomplete or ineffective treatment. At ADHD Assessment UK, our assessments routinely explore co-occurring conditions including anxiety, depression, and autism.