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Is ADHD a Mental Illness?

Posted on 14th December 2021 at 15:27

I’m very skilled at producing a shockingly loud whistle. I’m good at this because I spent hours and hours practising when I was about nine years old which probably wasn’t very relaxing for my family. By repeating the skill, over and over and over and over again, I developed pathways in my brain for making a loud whistling noise.

I recently discovered, when I had to attract the attention of someone a considerable distance away from me, that I can still do it, even though I haven’t done it for several years.

When you are learning a new skill, such as whistling, your brain is laying down a pathway. Like sheep tracks, the more you walk that way, the more you practice the skill, the clearer the path becomes. In the brain, chemicals called neurotransmitters, help make and develop these pathways.

ADHD is what’s called a “neurodevelopmental” condition. People with neurodevelopmental conditions can have difficulties making these pathways. ADHD is a condition linked with how the brain grows and changes and how it makes sense of information. ADHD develops in childhood and is usually a lifelong and permanent condition. It is highly heritable which means that it often runs in families.

In contrast to neurodevelopmental conditions, mental illnesses are psychological health difficulties which affect our emotions, our thoughts and our behaviour. They may come and go during our life and are not permanent conditions in the way that ADHD is. External events can cause or trigger mental health problems whereas ADHD is likely to affect a person whether or not things are going well in their life. So, ADHD is a “trait-like” condition which means that it is a permanent characteristic, like the colour of your eyes, whereas a mental illness is something that might last for a few months or years but which can be treated and which someone can recover from, like a broken leg.

People who have more stresses in their life, such as those who are disabled or live in very deprived areas of the country have higher rates of mental illness*. Depression and anxiety are examples of mental illnesses and may be triggered by difficult family circumstances, money problems, or other stresses caused by situations in the outside world.

For example, in May 2021, The Office for National Statistics reported that rates of depression in the UK had doubled since the Covid-19 pandemic began and that 21% of adults in the UK had experienced depression in the early part of the year.

So, mental illness is very common whereas only 3-4% of children and 1% of adults in the UK have ADHD**. Many adults in the UK who have ADHD are undiagnosed so it is probable that the majority of children with ADHD will continue to have ADHD as adults.

So, ADHD is not a mental illness. It is a neurodevelopmental condition. However, many people with ADHD also have one or more mental illnesses***. For example, having ADHD is very stressful and this may lead to a person having anxiety. It means that life is often a struggle and people with ADHD may be very self-critical and develop low self-esteem which may lead to depression. There may also be other mechanisms which mean that a significant number of people with ADHD also have bi-polar disorder. Someone with ADHD may have a mental illness (such as depression or anxiety) but ADHD itself, is not a mental illness.