Understanding the Common Co-Morbidities of ADHD

ADHD (Attention Deficit Hyperactivity Disorder) is more than just difficulties with attention, impulsivity, or restlessness. It’s a complex neurodevelopmental condition that often exists alongside other mental health or physical health challenges. These are known as co-morbidities (or co-occurring conditions), and they can make the experience of ADHD even more complicated to navigate.

Recognising and understanding these co-morbidities is an important step in managing ADHD effectively and compassionately—whether it’s for yourself, someone you love, or the clients you support.

What Are Co-Morbidities?

A co-morbidity is when two or more conditions are present in the same person at the same time. In the case of ADHD, it’s incredibly common to experience additional mental health difficulties or neurodevelopmental differences. Research suggests that over 60–80% of people with ADHD will have at least one co-occurring condition.

Let’s look at some of the most common ones.

1. Anxiety Disorders

People with ADHD often live with generalised anxiety, social anxiety, panic attacks, or obsessive thoughts. This anxiety can stem from the chronic stress of trying to keep up, facing constant overwhelm, or internalising criticism over the years.

Symptoms might include:

* Feeling constantly worried or on edge

* Difficulty relaxing or sleeping

* Avoiding certain situations due to fear or overthinking

Anxiety can sometimes mask ADHD—or even be mistaken for it—so it’s important to explore both together.

2. Depression

Living with untreated or misunderstood ADHD can be exhausting. When someone feels like they’re always falling short, missing deadlines, or not living up to their potential, it can take a toll on self-esteem. This can lead to low mood, hopelessness, and depression.

Signs might include:

* Persistent sadness or emptiness

* Loss of interest in things you usually enjoy

* Feelings of worthlessness or guilt

Depression in people with ADHD may show up in less obvious ways, especially if they’re good at masking or pushing through.

3. Autism Spectrum Condition (ASC)

ADHD and autism often co-occur, especially in women and non-binary individuals, where diagnosis can be late or missed entirely. While they’re distinct conditions, they can overlap in areas like:

* Sensory sensitivities

* Executive function challenges

* Social interaction differences

* Need for structure or routine

Understanding how the two interact can lead to more tailored support and reduce the pressure to ‘fit’ into neurotypical expectations.

4. Learning Difficulties

Many people with ADHD also have learning differences such as:

* Dyslexia (difficulties with reading, writing, spelling)

* Dyscalculia (struggles with numbers or maths)

* Dyspraxia (challenges with coordination and motor skills)

These differences aren’t a sign of low intelligence—they simply mean the brain processes information differently. But when left unsupported, they can lead to frustration and shame, especially in education or work settings.

5. Sensory Processing Differences

Many people with ADHD report being highly sensitive to noise, light, textures, or movement. While not always a standalone diagnosis, **sensory processing challenges** can make everyday environments feel overwhelming.

You might notice:

* Being easily startled or distracted by sensory input

* Discomfort with certain fabrics, lights, or background noise

* A strong need for calming sensory input to regulate

Sensory overload can impact focus, mood, and energy levels, so it's important to acknowledge and accommodate it.

6. Sleep Disorders

Struggling to fall asleep, stay asleep, or feel rested is incredibly common with ADHD. This can include:

* Delayed Sleep Phase Syndrome (feeling wide awake at night)

* Insomnia

* Restless sleep or waking frequently

Sleep issues can amplify ADHD symptoms, creating a difficult cycle of fatigue and brain fog.

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7. Rejection Sensitive Dysphoria (RSD)

While not an official diagnosis, Rejection Sensitive Dysphoria is a term often used to describe the intense emotional pain people with ADHD may feel in response to perceived rejection or criticism. It can feel like:

* Sudden emotional flooding after a negative comment

* Avoidance of conflict or feedback

* Deep feelings of shame or self-blame

RSD can be incredibly isolating and misunderstood—but with awareness and support, it’s possible to navigate these emotional storms more gently.

Why This Matters

ADHD rarely exists in a vacuum. Co-morbidities can impact how symptoms show up, how they’re interpreted by others, and what kind of support is most effective. Unfortunately, many people are only treated for the secondary condition (like anxiety or depression) without realising that ADHD might be the root cause.

Getting a holistic view of your mental health, through assessment, self-exploration, or neurodiversity-informed therapy, can help you feel more understood and less alone.

In Summary

If you or someone you care about is living with ADHD, it’s important to be aware of the co-occurring conditions that may be present. It’s not a sign of weakness or failure—it’s a sign that your brain processes the world differently, and that’s okay.

Understanding your full picture is the first step to finding the right strategies, support, and self-compassion to thrive.