Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by difficulties with attention, impulsivity and hyperactivity. It often begins in childhood and can persist into adulthood. ADHD affects around 5% of children and 2.5% of adults worldwide.
Many individuals with ADHD also experience co-occurring conditions such as anxiety disorders. Estimates suggest that up to 50% of people with ADHD have an anxiety disorder. This has led to speculation that untreated ADHD may directly cause or exacerbate anxiety.
In this article, we’ll explore the relationship between ADHD and anxiety, analyzing whether untreated ADHD leads to anxiety disorders. We’ll cover:
- The symptoms and causes of ADHD
- The link between ADHD and anxiety
- Theories on how ADHD could potentially cause anxiety
- Evidence for and against the idea that untreated ADHD causes anxiety
- The role of external factors in ADHD-related anxiety
- Conclusions on the ADHD-anxiety connection
Understanding this complex relationship is important for effective treatment and management of both conditions.
What are the symptoms and causes of ADHD?
ADHD has three core symptom domains:
- Inattention – Difficulty focusing, distracted easily, forgetfulness
- Hyperactivity – Excess movement, fidgeting, restlessness
- Impulsivity – Hasty actions, poor self-control, lack of patience
To receive a diagnosis, symptoms must be chronic, impair daily functioning, and not be better explained by another condition. There are three ADHD subtypes depending on the predominant symptoms:
- Predominantly inattentive type
- Predominantly hyperactive/impulsive type
- Combined type (both inattentive and hyperactive/impulsive)
ADHD is a neurodevelopmental disorder, meaning it originates from differences in brain development and neurotransmitter imbalances. Specifically, it is linked to:
- Structural differences in the frontal lobes, basal ganglia, corpus callosum and cerebellum
- Dysregulation of dopamine and noradrenaline neurotransmitters
- Genetic factors – ADHD tends to run in families
Environmental risks like premature birth, brain injury and exposure to environmental toxins may also play a role. Overall, it is a complex interaction between genetic, neurological and environmental factors that gives rise to ADHD.
What is the link between ADHD and anxiety?
Many studies over the past few decades have uncovered a strong association between ADHD and anxiety disorders.
The most common anxiety disorders linked to ADHD are:
- Generalized anxiety disorder
- Social anxiety disorder
- Specific phobias
- Obsessive compulsive disorder
- Panic disorder
Around 50% of adults with ADHD have met criteria for an anxiety disorder during their lifetime. Similarly, around 50% of children with ADHD also have anxiety.
Some key statistics on the ADHD-anxiety connection:
- 36% of adults with ADHD have general anxiety disorder
- 29% have social anxiety disorder
- 18% have obsessive compulsive disorder
- 16% have panic disorder
- 12% have specific phobias
Comparatively, only around 11% of the general population meets criteria for an anxiety disorder in a given year.
Clearly, anxiety disorders are far more prevalent among those with ADHD compared to the general public. But why is this the case? Let’s analyze some theories.
Theories explaining the ADHD-anxiety connection
There are several key theories that may explain why ADHD and anxiety overlap so frequently:
Theory 1: Shared genetic risk factors
ADHD and anxiety disorders share some genetic risk variants. Gene variants involved in serotonin and dopamine signalling have been implicated in both conditions. Having these variants may predispose someone to developing either disorder.
Theory 2: Dysfunctional neurotransmitter systems
As outlined earlier, ADHD involves dopamine and noradrenaline deficits in the prefrontal cortex of the brain. Anxiety disorders have been linked to abnormal serotonin signalling.
Having dysregulation in two different neurotransmitter systems may make someone more vulnerable to both ADHD and anxiety.
Theory 3: Overlapping brain abnormalities
Neuroimaging studies have uncovered structural and functional abnormalities in similar brain regions in people with ADHD and anxiety disorders:
- Prefrontal cortex
- Anterior cingulate cortex
- Amygdala
- Hippocampus
Again, overlapping neurological correlates may explain the strong comorbidity between the two conditions.
Theory 4: Cognitive deficits from ADHD cause anxiety
Core ADHD symptoms like inattention, forgetfulness, disorganization and poor planning could directly trigger anxiety in some individuals.
For example, someone who struggles with attentiveness may become anxious about their performance at school or work. Someone impulsive may act hastily in social situations, provoking later anxiety about others’ opinions of them.
Theory 5: Anxiety develops in response to ADHD impairments
Similarly, the functional and psychosocial impairments caused by ADHD could lead to secondary anxiety.
For instance, academic underachievement at school due to ADHD could cause anxiety about future prospects and self-esteem. Relationship difficulties due to impulsiveness could also provoke anxious thoughts and emotions.
In this view, anxiety arises as a natural response to the chronic stress and impairments of living with unmanaged ADHD.
Could untreated ADHD directly cause anxiety disorders?
Based on these theories and the strong comorbidity rates, it’s reasonable to hypothesize that ADHD could directly cause anxiety in some cases.
By this view, untreated ADHD – or residual symptoms despite treatment – generate anxiety symptoms as a downstream effect.
Studies provide some evidence both for and against this notion.
Evidence for
Some longitudinal studies have found that childhood ADHD predicts later anxiety disorders, even when controlling for other risk factors.
For example, a childhood ADHD diagnosis made someone 3.5 times more likely to develop an anxiety disorder by age 18 in one study. These findings suggest ADHD may directly cause anxiety.
Further backing this up, effective ADHD treatment with stimulant medication has been found to reduce anxiety symptoms in some cases. This indicates that minimizing ADHD impairments can lessen anxiety.
Evidence against
However, other studies suggest ADHD does not directly cause clinical anxiety disorders as a rule.
For instance, one study found no link between the severity of ADHD symptoms and the likelihood of having anxiety. If ADHD directly caused anxiety, worse ADHD would be expected to predict higher anxiety risk.
Additionally, some research indicates anxiety predates ADHD onset in around half of comorbid cases. This suggests anxiety arises completely separately in many individuals.
Overall, the exact nature of the ADHD-anxiety link remains unclear. Untreated ADHD may directly cause anxiety in a subset of cases. But in many comorbid patients, ADHD likely does not directly cause clinical anxiety disorders.
The role of external factors
While ADHD may directly generate anxiety in some people, in most cases other external factors are likely involved.
Potential contributing factors include:
Negative life experiences
The difficulties and impairments caused by ADHD may lead to negative life events like academic underachievement, interpersonal problems and low self-esteem. These experiences could provoke anxiety in any individual, with or without ADHD.
Stress
Managing the symptoms of ADHD under the chronic stress of school, work and family life may lead to anxiety. Stress can also exacerbate ADHD symptoms, which could worsen anxiety.
Harsh criticism
People with ADHD are often labeled as lazy, stupid, naughty, rude or weird due to their symptoms. Experiencing chronically negative reactions from parents, teachers or peers could understandably engender anxiety.
Psychiatric comorbidities
ADHD has links to other disorders like depression, bipolar disorder and substance abuse. These conditions carry their own risk for anxiety disorders, separate from ADHD itself.
So in many complex cases, anxiety is likely caused by ADHD symptoms mixing with external stressors and other psychiatric issues. ADHD may play an indirect role but is not necessarily the sole or even primary driver.
Conclusions
Untreated ADHD may directly cause anxiety symptoms and full anxiety disorders in some individuals. This likely results from chronic inattention, forgetfulness, disorganization and impulsivity provoking anxious thoughts and emotions.
However, in most comorbid cases ADHD probably does not directly cause clinical anxiety by itself. Instead, anxiety often arises from external factors like chronic stress, negative life events and comorbid psychiatric disorders. ADHD likely plays an indirect role by contributing to these secondary factors.
Overall, the relationship between ADHD and anxiety is complex. Effective management typically requires treating both conditions concurrently with a combination of psychotherapy, medications and lifestyle changes.
While ADHD may directly cause anxiety in some individuals, treating anxiety simply as a symptom of ADHD is often unwise. The origins of anxiety are multi-factorial and individualized, requiring careful assessment and personalization of treatment.
References
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Bowen, R.C., Chavira, D.A., Bailey, K., Stein, M.T. & Stein, M.B. (2008). Nature of anxiety comorbid with attention deficit hyperactivity disorder in children from a pediatric primary care setting. Psychiatry Research, 157(1-3), 201-209.
Jarrett, M.A., Wolff, J.C., Davis III, T.E., Cowart, M.J. & Ollendick, T.H. (2016). Characteristics of children with ADHD and comorbid anxiety. Journal of Attention Disorders, 20(7), 636-644.
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