co-occurring conditions

Written by Livia Farkas || First published: 28 June, 2023 | Last edited: 1 June, 2025 || 📚🕒 Reading Time: 7 minutes

In neurodivergence, co-occurrences are certain neurodivergent traits and conditions that tend to appear together in the same person: when you’re neurodivergent in one way, you’re more likely to experience other forms of neurodivergence too. Co-occurring conditions and co-occurring traits are very common in neurodivergence.

Patterns of co-occurrence in neurodivergence extend beyond neurodevelopmental differences: neurodivergent conditions are often co-occurrent with various physical and mental health conditions and experiences. Understanding co-occurrence is vital because it helps explain how different aspects of neurodivergence connect, leading to better self-understanding and more effective support. While traditional healthcare often treats conditions separately, recognising these natural connections can transform how you advocate for your needs and access appropriate care.

There are many overlapping traits and symptoms in neurodivergent conditions, so much so that some experts say that in the next decades, many of them will be merged into one group. It is possible to get multiple diagnoses because of this. ⁹

What is co-occurrence?

When you’re neurodivergent, it’s extremely common to experience multiple forms of neurodivergence together. This pattern, called co-occurrence, means that having one form of neurodivergence significantly increases the likelihood of having others ⁷. For example, between 30-80% of autistic people also have ADHD traits, while 20-50% of people with ADHD meet the criteria for autism ⁷.

But co-occurrence goes beyond just neurodevelopmental conditions. Research shows that neurodivergence often accompanies physical health differences as well ². This isn’t random – there are biological reasons why certain conditions tend to appear together. Scientists now understand that neurodivergence affects the whole body, not just the brain ¹.

This understanding represents a major shift in how we think about neurodivergence. Rather than seeing each condition as separate and isolated, we now know they’re often interconnected parts of how a person’s body and brain work together ⁶. This is why Dr. Gillberg introduced the concept of ESSENCE, emphasising that neurodevelopmental differences typically involve multiple areas of functioning rather than isolated symptoms ⁶.

Why understanding co-occurrence matters

Understanding co-occurrence can be life-changing for neurodivergent people. When you know that different traits and conditions often appear together, it helps make sense of experiences that might have seemed unrelated before. This knowledge is particularly powerful because many healthcare providers aren’t yet familiar with these patterns. Research shows that 69% of autistic adults have untreated health conditions ¹, often because their symptoms are viewed in isolation rather than as part of a larger picture.

For parents of neurodivergent children, understanding co-occurrence can be particularly valuable for early advocacy. When you know that certain conditions often appear together, you can be proactive about watching for signs and ensuring your child gets appropriate support early on, rather than waiting for challenges to become more severe ¹.

The impact of understanding co-occurrence extends throughout life. For example, if you’re diagnosed with ADHD, knowing about co-occurrence means you can recognise related conditions like sleep differences or sensory sensitivities. This awareness is especially important because neurodivergent people often experience physical health differences that can affect everything from digestion to joint flexibility ². In fact, research shows that over half of neurodivergent adults experience some form of joint hypermobility, compared to only 20% of the general population ².

For late-identified neurodivergent adults, learning about co-occurrence can help explain lifelong patterns that might have been dismissed or misunderstood. It’s common to have collected various diagnoses over the years, like anxiety or depression, without realising they might be connected to underlying neurodevelopmental differences ¹.

This understanding isn’t just about adding more labels; it’s about finding better strategies for support and self-advocacy.

Common patterns of co-occurrence

Neurodivergent traits and conditions often cluster together in predictable ways. One of the most well-documented patterns is between ADHD and autism. These two forms of neurodivergence share many underlying genetic and neurological features ⁷. Learning differences like dyslexia, dyscalculia, and dysgraphia also frequently appear together with both ADHD and autism, creating unique combinations of strengths and challenges.

Physical health patterns are equally important to recognise. Many neurodivergent people experience differences in how their autonomic nervous system works (called dysautonomia), which can affect everything from heart rate to digestion ². There’s also a fascinating connection between neurodivergence and the body’s connective tissue. This can show up as joint hypermobility or flexibility, and often comes with its own set of experiences like unusual pain patterns or difficulties with temperature regulation ².

The gut-brain connection is another crucial pattern. Recent research has revealed that the same systems that affect neurodivergent traits can also influence digestive health and immune system function ³⁴. This helps explain why many neurodivergent people experience digestive differences or food sensitivities – it’s all part of the same interconnected system.

Mental health & neurodivergence co-occurrences

Mental health patterns are also important to understand, but require a more nuanced view. While conditions like anxiety and depression are often diagnosed first, they can sometimes mask underlying neurodevelopmental differences ⁸. Research shows that over 70% of autistic adults experience at least one additional mental health condition ⁸.

However, it’s crucial to understand that many mental health challenges aren’t inherently part of being neurodivergent. They often develop as a natural response to navigating a world that isn’t designed for neurodivergent minds and bodies ¹.

Neurodivergent people face constant barriers to accessing appropriate support, experience repeated misunderstandings, or struggle to have their needs met in educational, workplace, and healthcare settings. It’s no wonder that anxiety and depression may develop ¹. Studies show that 69% of autistic adults have untreated health conditions ¹. This chronic lack of appropriate support and understanding can take a severe toll on mental health.

Understanding this shifts the focus from viewing depression and anxiety as inevitable co-occurring conditions to recognising them as often being the result of systemic barriers and unmet needs.

Know your co-occurrences for better support

Understanding co-occurrence can transform how you advocate for yourself in healthcare settings.

Instead of trying to address each symptom or condition separately, you can help healthcare providers see the bigger picture of how different aspects of your health connect ¹. This is particularly important because traditional medical practice often focuses on treating individual conditions, potentially missing important connections that could lead to more effective support.

For example, if you’re seeking help for chronic pain, knowing about the connection between neurodivergence and joint hypermobility might help you and your healthcare provider find more appropriate treatments ². Similarly, understanding that sleep differences and sensory sensitivities often go hand-in-hand with neurodivergence can help you advocate for solutions that address root causes rather than just managing symptoms.

Parents can use this knowledge to advocate for comprehensive assessments and support for their children. For example, if your child has been identified as autistic, understanding co-occurrence might help you recognise and address sensory needs or learning differences earlier, leading to better educational outcomes and reduced stress for your child.

This knowledge is equally valuable in other areas of life. In educational or workplace settings, understanding how different aspects of neurodivergence interact can help you request accommodations that address your full range of needs. For instance, if you know that ADHD and sensory processing differences often co-occur even without an autism diagnosis, you might advocate for both organisational support and sensory-friendly workspace adjustments.

Knowing about co-occurrence extends diagnoses

Remember that you don’t need to have formal diagnoses of co-occurring conditions to benefit from this understanding. Even if your traits don’t meet current diagnostic thresholds or are considered “subclinical,” neurodivergent-friendly approaches can still significantly improve your quality of life ⁶. The goal isn’t to collect labels, but to better understand your experiences and needs. This knowledge can help you recognise patterns in your own life and seek appropriate support, even if traditional diagnostic categories don’t perfectly capture your experience ¹. Understanding co-occurrence can help explain why strategies designed for neurodivergent people might work well for you, even if you don’t fully meet diagnostic criteria for any single condition.

Making sense of your journey

Learning about co-occurrence can stir up many emotions. You might feel relieved to finally understand connections between experiences you’ve had your whole life. You might also feel frustrated or angry about not having this information sooner. Both reactions are completely valid. The reality is that our understanding of how neurodivergent traits and conditions connect is still relatively new in the medical world ¹, and this knowledge hasn’t yet made its way into many healthcare settings.

It’s common to look back and realise that signs of co-occurring conditions were there all along, but weren’t recognised because they were viewed in isolation. This is particularly true for people assigned female at birth, who often go undiagnosed or are misdiagnosed for years ¹. Understanding co-occurrence can help explain why certain treatments or approaches might not have worked well in the past – they might have been addressing individual symptoms without recognising the broader pattern.

A new context for overlapping neurodivergent traits

Remember that discovering these connections isn’t about finding more “wrong” with you – it’s about understanding yourself better and finding more effective ways to support your needs.

Research increasingly shows that neurodivergence affects whole-body systems in interconnected ways ², and this understanding is gradually shifting healthcare towards more holistic approaches. Your experiences are real and valid, even if they weren’t always recognised or understood by others.

While it can feel overwhelming to learn about all these connections, this knowledge is ultimately empowering. Understanding co-occurrence can help you make sense of your past experiences, better advocate for your needs in the present, and make more informed decisions about your support and care in the future.

For parents, learning about co-occurrence can help you understand both your child’s experiences and, sometimes, your own. Given that neurodivergence often runs in families ¹, this knowledge might illuminate patterns across generations, leading to a better understanding and support for everyone involved.