In short
- ADHD is a neurodevelopmental condition: it relates to how the brain develops and works.
- Genes play the biggest part. ADHD often runs in families.
- Being born early, low birth weight, epilepsy and brain injury are linked to a higher chance of ADHD.
- Sugar, screens and bad parenting do not cause ADHD.
- Most of the time there is no single cause, and nothing you did or did not do made it happen.
What causes ADHD in children is one of the first questions parents ask, often quietly, and often with a worry underneath it: did I do something to cause this? The short answer is no. ADHD is a neurodevelopmental condition, shaped mainly by genes and by how the brain develops. It is not caused by parenting, by diet or by too much television.
The fuller answer is that the causes are not completely understood, even though ADHD is one of the most researched conditions of childhood. What researchers do know points to a mix of inherited and early developmental factors. This guide sets out what the evidence shows, the myths that still do the rounds, and why blame has no place in any of it.
Is ADHD genetic?
Genes are the strongest known factor. ADHD often runs in families, and the NHS describes genetic differences as a likely cause. NICE guidance notes that family members are frequently affected.
Studies of twins give the clearest picture. They suggest that around three quarters of the variation in ADHD traits between people is explained by genetics.
There is no single "ADHD gene". It seems that many genes, each with a small effect, work together. That is part of why ADHD looks different from one child to the next.
Is ADHD hereditary? What it means for your family
If a parent, brother or sister has ADHD, a child is more likely to have it too. NICE points out that ADHD in parents may have been missed when they were young, and should be considered.
It is very common, during a child's assessment, for a mum or dad to say: "That was me at school." If that rings true for you, it is not a cause for guilt. It can be a relief, and it often means you understand your child better than anyone. Having ADHD yourself can also make the organisation of family life harder, and NICE recognises that parents in this position may need extra support.
Are you born with ADHD?
ADHD relates to how the brain develops and works, so in that sense it is part of who a child is from early on. NICE's clinical summaries describe a mix of genetic and environmental factors that are thought to lead to differences in brain chemistry and structure. Those differences affect attention, activity levels and self-control.
The signs usually show in childhood, but they are not always recognised straight away. Some children cope until school demands rise, for example in the later primary years, at the move to secondary school or around exams. That does not mean ADHD started then. It means the gap between what your child is being asked to do and what they can manage became visible.
There is still no blood test or brain scan that can diagnose ADHD in an individual child. Diagnosis rests on a careful clinical assessment.
Other causes of ADHD in children: known risk factors
Some early factors are linked to a higher chance of ADHD. The NHS and NICE list:
- being born prematurely, before 37 weeks of pregnancy
- low birth weight
- epilepsy
- a brain injury
- other neurodevelopmental conditions, such as autism, tic disorders and learning difficulties
NICE's clinical summaries also mention exposure to smoking or alcohol during pregnancy, lead exposure and iron deficiency, and note that difficult life circumstances are associated with ADHD.
A risk factor is something seen more often in children with ADHD. It does not mean that factor caused ADHD in any particular child, and it is not a verdict on anyone. Pregnancies and early lives are rarely perfect, and these links describe patterns across large groups of people, not choices made in your family.
Difficult life events, such as a bereavement, a house move or a family break-up, can make any child unsettled and distracted. The NHS notes that tiredness, anxiety and stress can look very like ADHD. Part of a good assessment is telling these apart, which is why the doctor will ask about your child's whole life, not just their behaviour.
Myths about what causes ADHD
Does sugar cause ADHD?
No. This is one of the most widely held beliefs, and it has been tested carefully. In the best studies, children were given either sugar or a sweetener, and neither the children, their parents nor the researchers knew which. A review that pooled these studies found no clear effect of sugar on behaviour or concentration. The authors suggested that parents' strong belief may come from expectation and from the settings, such as parties, where sweets are eaten.
A healthy, balanced diet and regular mealtimes still help. NICE advises that a food and drink diary can be useful if you notice a particular food seems to affect your child, and that any further change to diet should be planned with a dietitian. NICE does not recommend removing artificial colourings and additives as a general treatment for ADHD.
Do screens cause ADHD?
Screens are not listed as a cause of ADHD in NHS or NICE guidance. But heavy screen use can cause restlessness, poor sleep and poor focus that look like ADHD, and children with ADHD often find their symptoms worse with lots of screen time. So screens are worth managing, especially before bed, but they are not why your child has ADHD.
Is ADHD caused by bad parenting?
No. This myth causes more hurt than any other, and it is still heard far too often, sometimes from professionals.
ADHD is not caused by parenting
We want to say this plainly, because many parents arrive at their first appointment having been made to feel it is their fault. ADHD is not caused by how you love, discipline or raise your child.
Children with ADHD can be harder to parent. They often need more structure, more patience and more repetition than other children, and family life can become tense and tiring as a result. That strain is a consequence of the ADHD, not its cause. NICE guidance is clear that when parenting support is suggested, it does not imply bad parenting. Its purpose is to help parents meet the above-average parenting needs of a child with ADHD.
Your observations matter, too. You see your child at breakfast, at bedtime, on good days and bad ones. That knowledge is valuable information for any doctor assessing them, not "just a feeling".
Dr Bozena Zoric has written a book about this: ADHD, Attachment Theory and Epistemic Injustice (Routledge, 2026), on how mothers in particular can be wrongly blamed in ADHD pathways. You can read more on our page When parents feel blamed in ADHD pathways.
Why the cause matters less than the support
Knowing the likely causes can lift a weight, especially the weight of blame. But for your child, the more useful question is what will help now. Children with ADHD have real strengths, such as creativity and energy, and with the right understanding at home and at school they can do very well. Our page on the many good things about ADHD is a reminder of that.
If you think your child may have ADHD, you can start with our free ADHD questionnaire, talk to your GP or the school's SENCO, or contact us about a private ADHD assessment for your child. Our doctors are consultant paediatricians, every appointment is face to face, and you do not need a GP referral.
Questions parents ask
Is ADHD genetic?
Genes play a large part. ADHD often runs in families, and studies of twins show that much of the difference between people in ADHD traits is explained by genetics. There is no single ADHD gene. Many genes, each with a small effect, seem to be involved.
Are you born with ADHD or does it develop?
ADHD is a neurodevelopmental condition, which means it relates to how the brain develops from early life. Signs usually show in childhood, even if they are only recognised later, for example when school becomes more demanding. It does not appear because of something that happened in a family's home life.
Is ADHD hereditary in the UK?
ADHD is hereditary wherever you live. If a parent, brother or sister has ADHD, a child is more likely to have it too. It is quite common for a parent to recognise their own childhood in their child's assessment.
How did my child get ADHD?
Usually through a mix of inherited genes and, sometimes, early factors such as being born prematurely. In most cases no single cause can be found. It is not caused by anything you did as a parent.
Does sugar cause ADHD?
No. Careful studies in which neither parents nor children knew whether a drink contained sugar found no clear effect on behaviour or concentration. A healthy, balanced diet still helps every child feel and focus better.