Why wasn’t I diagnosed with ADHD as a child?

Why wasn’t I diagnosed with ADHD as a child

ADHD was traditionally thought of as a child’s condition and something that would usually be outgrown by adulthood, fast-forward a few decades and we now have a far better understanding of how different ADHD can present in men, women, and children. Around 2.6 million people in the UK are thought to have ADHD, making up 2% to 5% of school children and between 3% and 4% of adults. 

Individuals with ADHD are often described as horizontal thinkers, moving from one task to the next, often leaving them unfinished. Whereas vertical thinkers, those without ADHD, can prioritise, finish a task and move on to the next.

With an increased understanding of the condition and a prevalence of curiosity around it, we are now seeing more and more adults gaining an assessment and diagnosis to gain answers to some of their struggles. Let’s look at some of the reasons so many adults today were misdiagnosed as children.

What are the signs and symptoms of ADHD?

Unfortunately, there isn’t a one size fits all approach to recognising signs of ADHD, it presents differently in men and women, children, and adults. There are 3 main types of ADHD; impulsivity and hyperactivity, inattentiveness, and combined.  

Impulsivity and Hyperactivity

People with hyperactivity and impulsivity tend to feel the need for constant movement, often fidgeting and struggling to stay still. Children with this type of ADHD may appear to have endless energy, run around excessively, and appear to be “run by a motor”. Adults with this type of ADHD may still experience extreme restlessness, excessive talking, difficulty with self-control, and a desire for immediate rewards.


People with inattentive ADHD find it difficult to sustain their attention and follow detailed instructions. They may make careless mistakes due to this and find it difficult to organise tasks and activities. Their memory may also be affected, being easily distracted, and lose things. For children this may show in schoolwork, making careless mistakes, forgetting, and losing things, and being unable to stick to time-consuming and tedious tasks. It is much the same for adults, except that it can quickly become detrimental to their job and family life.


People with the combined type of ADHD will show 6 or more symptoms of inattention and 6 or more symptoms of hyperactivity and impulsivity.

How ADHD can go undiagnosed throughout childhood

ADHD can be missed in children for many reasons, one being that practitioners simply haven’t had specialised training in childhood disorders, meaning that when a child is brought to their GP, ADHD may not be on the doctor’s radar. The Diagnostic and Statistical Manual of Mental Disorders, the primary reference for mental health practitioners, didn’t include ADHD in its first edition. When it did show up in the second edition in 1968, the write-up was brief and stated that the condition will disappear by adulthood.  

Another big factor in undiagnosed ADHD in children is the structure and routine of school. Having a schedule and structure for the day may make it easier for children with ADHD to function. Later in life, when it comes to higher education, families, and work life, staying focused on projects can prove difficult, and organising children’s activities, paying bills, and keeping appointments can cause overwhelm and burnout.

Masking and hiding signs of ADHD is another coping mechanism among school children, firstly due to the stigma. If the child is old enough to be aware of “differences” from other children, it can feel like they are not trying hard enough and appear this way to others.

How ADHD presents itself in adulthood

In adulthood, ADHD can present very differently, even for males and females. Men are typically diagnosed with hyperactivity and impulsivity ADHD type. While the hyperactivity often wanes by adulthood, the person usually learns to manage the symptom better, the impulsivity does not. Women are more often diagnosed with the inattentive type of ADHD, appearing distracted, in a daydream, experiencing memory problems, finding it difficult to concentrate, and dealing with procrastination. 

 Alongside this ADHD symptom and the hurdles and barriers that crop up, anxiety and depression can arise, either as a symptom of dealing with ADHD or a recurrent mood and anxiety disorder that punctuates the ADHD periodically. It is more likely for women and girls to be misdiagnosed or receive an incomplete diagnosis due to mental health struggles and often when women or girls visit their doctor with anxiety or depression, it is this symptom that is treated and not the underlying cause.

Gaining a diagnosis now through a specialist ADHD clinic

Studies show that genetics is the main cause of ADHD and not the environment. The condition tends to run in families, often if your siblings, mother, or father have a diagnosis, chances are that you will have ADHD too. So, if you think that you may have ADHD, it can be extremely beneficial to gain a proper assessment with an ADHD psychiatrist.

It’s important to keep in mind that research and understanding around ADHD is still in its infancy, which is why so many men and women are often left undiagnosed, but it’s equally important to know that help is available. 

Sanctum is a specialist ADHD clinic offering a comprehensive, multi-professional assessment for adults and children who may have ADHD. Sanctum’s diagnostic team all have specialist experience in assessing and supporting individuals with ADHD. Private ADHD clinics such as Sanctum understand the struggles of living a full and happy life with undiagnosed ADHD, that’s why we offer rapid access to assessment to ensure that you can gain the diagnosis you require and take steps to ensure that you live the life you desire.

If you would like to speak to Sanctum’s friendly team about obtaining an ADHD assessment, you can get in touch here.

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