Sam Thompson is set to explore whether he has Attention Deficit Hyperactivity Disorder (ADHD) in a new E4 documentary.

The former Made in Chelsea star, 30, made the decision after his family and friends, as well as girlfriend Zara McDermott said he'd been displaying signs for years.

But last year as he approached his 30th birthday, Thompson made the decision to finally get tested for ADHD and explore what a possible diagnosis might mean for him.

The NHS describes ADHD as a condition that affects people’s behaviour, and people who have ADHD can seem restless and may have trouble concentrating.

The former reality TV star says he is known by those close to him for his impulsiveness, for forgetting appointments and losing things like car keys.

Speaking about the upcoming E4 programme, Sam Thompson: Is This ADHD?, he says: "This documentary is the most vulnerable I’ve felt in front of the camera, as I wanted to be totally open about how I react to people in situations, and whether these could be linked to ADHD.

"It has been an incredible, and at times, scary experience, but by exploring what’s been going on inside my head, I hope people can see that we should be more understanding before judging others. I also want to encourage people to learn more about themselves, and be proud of everything that makes them unique.”

News of the documentary comes after Olivia Attwood previously discussed being diagnosed with ADHD as an adult, revealing how it impacts her every day life.

The former Love Island contestant, 31, spoke about the condition while appearing on ITV's Loose Women, explaining that she was diagnosed while seeking treatment for anxiety and depression.

"Later in life I found myself with a severe battle of anxiety and depression, and came under the care of a psychiatrist who specialised in ADHD," she said.

"It was a stroke of luck that it was diagnosed. [It's a] state of being constantly overwhelmed."

When asked about what type of ADHD she had, the reality TV star replied: "There are three major types. I fall into a combined type...

"There’s the typical type people look for – hyperactive child in the classroom, throwing things, breaking things. Other types [include] internalised, fidgeting, restless thoughts, disorganised, acting on impulse."

Read more: Woman diagnosed with ADHD at 44: 'I thought it only affected young boys'

The TV personality also shared why she is choosing to openly discuss her condition.

"I'd not heard others speak about it so I kept it to myself," she revealed.

"It only came out by accident on Instagram stories. I got loads of DMs from young women and mothers, who wanted to hear more."

Read more: Why so many women are only diagnosed with ADHD in adulthood

Johnny Vegas also recently shared details about his own ADHD diagnosis, revealing it has “answered a lot of questions”.

The comedian, 52, was diagnosed last year, and told BBC Breakfast that he is in the “early stages of working through meds”.

“Eventually I sort of bit the bullet and went in, and I've got friends who have been diagnosed,” Vegas told presenters Jon Kay and Sally Nugent.

“So I'm in the very early stages of working through meds and things like that. It just answers a lot of questions about behavioural issues in the past.”

What is ADHD?

Many think of ADHD as a childhood condition, as that is often when it is diagnosed, but a growing number of people in the UK are sharing experiences of being diagnosed with the condition in adulthood.

Research reveals around 2.5% of adults are thought to be living with ADHD, but despite this figure and a growing awareness, many people still struggle to get a diagnosis.

According to the NHS, ADHD is a condition that affects people's behaviour. People with ADHD can seem restless, may have trouble concentrating and may act on impulse.

The exact cause of ADHD is unknown, but it has been shown to run in families.

Research has also identified a number of possible differences in the brains of people with ADHD when compared with those without the condition.

“ADHD is at its core an attention problem, and when our attentional processes malfunction, that can impact on many different areas of the way we function as people," explains consultant psychiatrist, Dr Paul McLaren.

"Typically ADHD is thought of as the restless pupil who cannot sit at a desk to complete a piece of work."

Watch: Shaun Ryder opens up about how his ADHD led to his drug abuse.

What are the symptoms of adult ADHD?

While symptoms are similar for both adults and children, elements differ or change as we age.

In adults, the NHS says symptoms of ADHD are more difficult to define. This is largely due to a lack of research into adults with ADHD.

"Adult symptoms of ADHD also tend to be far more subtle than childhood symptoms," the NHS explains.

Some specialists have suggested the following as a list of symptoms associated with ADHD in adults:

- carelessness and lack of attention to detail

- continually starting new tasks before finishing old ones

- poor organisational skills

- inability to focus or prioritise

- continually losing or misplacing things

- forgetfulness

- restlessness and edginess

- difficulty keeping quiet, and speaking out of turn

- blurting out responses and often interrupting others

- mood swings, irritability and a quick temper

- inability to deal with stress

- extreme impatience

- taking risks in activities, often with little or no regard for personal safety or the safety of others – for example, driving dangerously.

According to McLaren, other symptoms include problems with impulsivity, forgetfulness and distractibility.

"These symptoms can lead to being accident prone," he adds. "Problems with listening in meetings can impair performance at work.

"The attentional problems can also have an impact on close relationships, with partners feeling that they are not listened to - or attended to - in conversations."

Read more: Three reasons your to-do list is not getting done if you have ADHD

How is ADHD treated?

Although there's no cure for ADHD, the NHS says it can be managed with advice, support and appropriate educational support, alongside medicine, if necessary.

Dr Dimitrios Paschos, consultant psychiatrist at Re:Cognition Health recommends getting a clear diagnosis before seeking treatment.

"Unfortunately an incorrect diagnosis of ADHD can be made if a thorough assessment has not taken place. Missing a case of ADHD or diagnosing it when it is not present can be equally damaging," he explains.

"If you’re worried about yourself or your child, talk to your GP and ask for an evaluation. Medication may be prescribed to relieve the symptoms and there are also many other ways to reduce the impact of ADHD symptoms that include talking therapies and lifestyle management.

Dr Paschos adds that there are also new treatments on then horizon and new technologies can help more people with ADHD achieve their full potential.

Signs and symptoms of ADHD in children

According to the NHS the symptoms of ADHD in children and teenagers are well defined.

Children may have symptoms of both inattentiveness and hyperactivity and impulsiveness, or they may have symptoms of just one of these types of behaviour.

Inattentiveness (difficulty concentrating and focusing)

The main signs of inattentiveness are:

• having a short attention span and being easily distracted

• making careless mistakes – for example, in schoolwork

• appearing forgetful or losing things

• being unable to stick to tasks that are tedious or time-consuming

• appearing to be unable to listen to or carry out instructions

• constantly changing activity or task

• having difficulty organising tasks

Hyperactivity and impulsiveness

The main signs of hyperactivity and impulsiveness are:

• being unable to sit still, especially in calm or quiet surroundings

• constantly fidgeting

• being unable to concentrate on tasks

• excessive physical movement

• excessive talking

• being unable to wait their turn

• acting without thinking

• interrupting conversations

• little or no sense of danger

This article was first published in June 2021 and has been updated