Thousands of people in the UK battle with ADHD or Attention Deficit Hyperactivity Disorder but few really understand it.
Symptoms are different for every sufferer and include depression
About 20% of children suspended from school suffer from the disorder, according to Professor of Psychiatry Philip Asherson.
But so many myths surround the condition that parents could be unaware that their child is affected.
Monica Harris is executive director of an ADHD family support group in Milton Keynes and her son Nathan was diagnosed with ADHD when he was 12.
She said: "When I found out my son had ADHD, you just don't understand the relief that was off my shoulders.
"Before then I was told it was my fault. I was deemed a bad parent, I couldn't control my son."
'I act on impulse'
Every ADHD sufferer is different but symptoms can include hyperactivity, impulsiveness, anxiety, depression and compulsion.
Nathan, now 24, described how the disorder affects him: "ADHD makes me feel a bit different from other people.
"I don't think the same way as other people. I don't act the same way as other people. I act on impulse. I can't concentrate on other things.
"School was hell for me… getting suspended, detention, always getting shouted at by teachers, always humiliated in front of my class."
Nathan left school at 16 and "fell in with the wrong crowd". He was in and out of prison from the age of 18.
Phil Anderton worked as a police officer for 27 years and specialised in helping young people with ADHD.
He said: "There's a lot of research to suggest that towards 25% of our prison population have ADHD, whilst only 5% of the general population have ADHD. So that disproportionality gives us an indicator of the scale of the issue.
"Two out of three sentenced young women and four out of five sentenced young men are believed to have ADHD or some other mental health disorder."
However, Nathan felt he didn't get the support he needed in prison.
At times he felt people thought he was using ADHD as an excuse to get out.
Anderton also recognised this as an issue.
He said: "I can't possibly begin to empathise with what it must be like to be poorly, to be misunderstood and for them to deliberately label you as a person that should not be allowed in society - that somebody's choosing to break the rules of society.
"I just can't understand the effect that will have on young people."
Many adults can also struggle with ADHD-related problems
Without more awareness of the disorder, many parents and children could face similar problems to Nathan.
As Nathan's mum worries: "There is a danger that we are not diagnosing in the UK, we are under-diagnosing in the UK. Not only are they being missed by the system, they are being missed by their parents."
ADHD is not just a problem that affects children - research suggests one in five who had it as a child still have the problem to a severe degree when they are 25-years-old.
Up to two thirds of people have problems related to ADHD when they are adults.
Prof Asherson added: "Surveys have shown how adults with ADHD are much more likely to be unemployed, they have problems keeping friends, just doing simple things like paying the bills. They are four times more likely to have contracted a sexually transmitted disease."
The biggest problem sufferers have is dispelling the many myths that have built up around the condition.
Nathan said: "My advice to other ADHD people is if you can't get help out there, try and help yourself as much as you can.
"There are support groups out there that can help you. People can help other people with ADHD if they learn to understand."
Nathan now has children and is looking forward to getting married and settling into a job.