Diagnosed with ADHD as an adult: what to expect

I’m Ross, and I built Yoodoo. I’ve had about 20 careers and something like 70 jobs. I became a senior product designer, at Spotify and Ticketmaster, and for years I built my own system to hold my days together. When it became an app, people kept telling me it was the first thing that had worked for their ADHD brain. After three years of hearing that, I got assessed. I was diagnosed at 39.

How common it is

More common than most people think. A 2021 global review of population studies estimated that, adjusted to the world’s population in 2020, 2.58% of adults had ADHD that started in childhood and carried on into adulthood. Counting adults with ADHD symptoms whatever their childhood history, the figure was 6.76%.¹

The diagnostic criteria say symptoms should have started in childhood, before age 12.² But plenty of people get through school and into adult life without anyone putting a name to it.

Why it gets missed

There are lots of reasons. Some people build ways of coping that hide what’s going on underneath. Others are told they’re lazy, disorganised or “not living up to their potential”, and believe it.

It’s especially likely to be missed in women. The NHS says ADHD is recognised less often in women than men, possibly because women more often have inattentive symptoms, and those are harder to spot than hyperactive ones.³ NICE guidance tells UK clinicians that girls and women are less likely to be referred for assessment, more likely to have undiagnosed ADHD, and more likely to be given a wrong diagnosis of another condition instead.⁴

A UK expert consensus on women and girls with ADHD pointed to several barriers: symptoms that look different, gender bias, other conditions that overshadow the ADHD, and coping strategies that mask it.⁵

What assessment looks like in the UK

Start with your GP. The NHS says to see a GP if ADHD symptoms are affecting your studies, work or relationships. They can refer you for an assessment.³

A specialist does the assessment. Under NICE guidance, ADHD should only be diagnosed by a specialist psychiatrist or another suitably trained professional. It’s based on a full clinical and psychosocial assessment, including your history from childhood and how symptoms show up in different parts of your life. A diagnosis shouldn’t be made from a rating scale alone.⁶

Expect questions about your whole life. The NHS says the specialist will ask about work and education, family and friends, and your medical history including mental health. They’ll ask about the history of your symptoms, particularly whether they started in childhood. They may also want to speak to someone who knows you well, like a family member.³

Expect a wait. The NHS says waiting times vary and can be several months or years. In England you may be able to use the Right to Choose scheme, through your GP, to pick a provider with a shorter list.³

What the criteria say

UK clinicians use the DSM-5 or ICD-11 criteria. For a diagnosis, NICE says the symptoms should cause at least moderate problems in your life and show up in two or more important settings, such as home and work.⁶

The US Centers for Disease Control and Prevention summarises the DSM-5 criteria. For people aged 17 and over, it asks for five or more symptoms of inattention and/or five or more of hyperactivity and impulsivity. Several symptoms must have been present before age 12, in two or more settings, and they must clearly interfere with or reduce the quality of your life.²

Only a qualified clinician can diagnose ADHD. Online quizzes can help you decide whether to ask, but they can’t tell you whether you have it.

The feelings afterwards

A diagnosis can bring a lot up, often all at once.

In a small UK study, eight adults described what happened after they were diagnosed. The researchers grouped it into stages: relief and elation, then confusion and emotional turmoil, anger, sadness and grief, anxiety, and finally accommodation and acceptance.⁷ Eight people is a small number, so treat it as a description, not a rule. You might feel all of these, some, or none, and not in that order.

Relief is common. There’s a reason, and it isn’t that you didn’t try. Grief is common too, for the years that might have gone differently. So is anger, at the people who missed it.

NICE recommends that, after a diagnosis, clinicians talk with you about how ADHD might affect your life. That includes the upsides, like understanding your symptoms and building on your strengths, and the downsides, like stigma.⁶

What helps

• Give yourself time. You don’t have to work out what it all means this week.
• Ask your clinician about support. Treatment and therapy options are a conversation for you and your GP or specialist. They know your situation.
• Find your people. Hearing how other adults with ADHD manage can make it feel less lonely.
• Start small with the practical stuff. Get what’s on your mind out of your head with a brain dump. On the hard days, make the day smaller. At night, a short wrap up gives tomorrow some shape.

A diagnosis doesn’t change who you are. It gives you a better map of how you work.