For many individuals, ADHD comes hand-in-hand with other conditions that can shape how symptoms appear, how they're treated, and how much they affect day-to-day life. This is where the term ‘Complex ADHD’ comes into play – a concept that acknowledges the layered reality of living with ADHD alongside other challenges.
At Beyond Clinics, a private ADHD clinic in Manchester, we recognise that ADHD isn’t an illness – it’s a neurodevelopmental condition that comes with its own strengths and difficulties. And when there’s more than one condition in the mix, things can feel especially complicated. But with the right understanding and support, people with Complex ADHD can absolutely thrive.
What Is Complex ADHD?
Complex ADHD is a term used to describe when ADHD coexists with one or more additional conditions, such as anxiety, depression, learning differences, or neurodevelopmental disorders like autism. It also refers to the varied and often intricate ways ADHD can present from one person to the next.
It’s important to attribute a name to this phenomenon, as co-occurring conditions aren’t the exception – they’re the norm. Research suggests that around 80% of adults and 60% of children with ADHD have at least one other mental health condition. Amongst the most common conditions are anxiety, tics or Tourette’s, learning difficulties like dyslexia or dyscalculia, mood disorders, and substance use issues.
It is this interaction between ADHD and other conditions which can make it harder to diagnose, treat, and manage. This is because symptoms might overlap or mask each other, and sometimes treating one condition can inadvertently worsen another. Looking at it through the lens of complex ADHD allows clinicians to look at the whole picture, rather than just one small part of a greater puzzle.
Why the Term ‘Complex ADHD’ Matters.
While clinicians have long been aware of how often ADHD appears alongside other conditions, the term ‘Complex ADHD’ has come about from an effort to shift thinking towards a more nuanced, compassionate, and holistic understanding of the condition.
This is particularly important as these co-occurring conditions often change as people grow. For example, externalising behaviours, such as conduct disorders, are far more common in children. While in adults, internal experiences like anxiety or depression are more likely co-occurrences with ADHD. Understanding how complex ADHD might grow and develop means that diagnoses and treatment plans worked out in childhood can more easily adapt over time as our understanding of ADHD grows with the person.
What Causes Co-Occurring Conditions?
While it’s not entirely clear what causes co-occurring conditions, current research suggests that shared neurological pathways and differences in brain development – particularly in the prefrontal cortex – might underpin both ADHD and many of the conditions that come with it. This helps to explain why ADHD can look so different from one individual to another. It’s also why many experts now view ADHD not as a single set of symptoms, but as a spectrum condition in a similar way to autism. This means that it is a condition that varies widely depending on the person and their environment.
How Is Complex ADHD Diagnosed?
Diagnosis begins by establishing whether someone meets the criteria for ADHD on its own – usually using standard tools like the ADHD Rating Scale-5 or the Conners Rating Scale. For adults, five or more symptoms of inattention and/or hyperactivity-impulsivity are needed. In children, the standard is slightly higher, requiring six or more symptoms of inattention and/or hyperactivity-impulsivity.
Once this is established, clinicians go further to determine whether or not there is anything else going on. For example, whether there’s anxiety, a learning difference, or personal life changes which could affect behaviour. Sometimes, clinicians will refer those seeking diagnosis to specialists to assess for co-occurring conditions using other tools.
According to current expert guidelines, a person might be considered to have Complex ADHD if:
- They show signs of multiple overlapping conditions (like learning disorders, mental health issues, or autism).
- Their case is diagnostically unclear or unusually complex.
- They haven’t responded to standard treatment.
- They’re very young (under 4) or older (over 12) when symptoms first appear.
Treating Complex ADHD.
When it comes to treatment, the old thinking was to address co-occurring conditions first, and then turn to ADHD. But current best practice suggests a more balanced, person-centred approach: to treat ADHD and the co-existing conditions at the same time, wherever possible. The reasoning behind this is because supporting ADHD can often lead to improvements in other areas, whereas ignoring one part of a bigger picture can make the entire treatment process more difficult.
The methods for making a comprehensive treatment plan for Complex ADHD can vary hugely but usually include some of the following: medication, talking therapies, executive function coaching, parent training, and fostering healthy habits. It’s also helpful to set clear goals from the outset and track progress over time. This could mean keeping a symptom diary or working with a clinician to regularly check in on what’s improved – and where extra support might be needed. Beyond Clinics pride themselves on their experience and expertise in assessing, diagnosing and treating ADHD, offering comprehensive and tailored treatment plans for both adults and children.
Embracing Complexity.
At Beyond Clinics, we recognise that living with ADHD – especially when it’s complex – can come with very real challenges. But we also recognise that it can come with deep self-awareness, creativity, resilience, and insight. No two people with ADHD are the same, and no treatment plan should be either. Whether it’s a new diagnosis or someone exploring new treatment options, Beyond Clinics are there to offer support and to help navigate the complexities of ADHD with confidence and compassion.
