What Are the DSM-5 Diagnostic Criteria for ADHD?

This guide explains the DSM-5 ADHD criteria in plain language, including the signs clinicians look for, and why age, timing and everyday impact all matter.

The DSM-5 is the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association. It sets out clear criteria so that ADHD is diagnosed consistently, wherever someone is assessed.

In the UK, NICE guidelines say an ADHD diagnosis should meet either the DSM-5 or the ICD-11 criteria. The two are very similar, and most specialists draw on both.

The DSM-5 describes nine signs of inattention and nine signs of hyperactivity and impulsivity. In plain language, these are:

Inattention

• missing details or making careless mistakes
• finding it hard to keep focus on tasks, conversations or reading
• seeming not to listen when spoken to directly
• not following through on instructions, or leaving tasks unfinished
• difficulty organising tasks, time and belongings
• avoiding tasks that need sustained mental effort
• often losing things
• being easily distracted
• forgetfulness in daily activities

Hyperactivity and impulsivity

• fidgeting, tapping or squirming
• leaving your seat when you're expected to stay put
• running or climbing at the wrong times in children, or feeling restless in adults
• finding it hard to play or relax quietly
• being "on the go", as if driven by a motor
• talking a lot
• blurting out answers before a question is finished
• finding it hard to wait your turn
• interrupting or intruding on others

Everyone has some of these experiences from time to time. For ADHD, they need to happen often, and more than would be expected for someone's age and stage of development.

The number of signs needed depends on age:

• Children up to the age of 16 need at least six signs of inattention, or six of hyperactivity-impulsivity, or both.
• Young people aged 17 and over, and adults, need at least five in either group, or both.

The threshold is lower for adults because ADHD often becomes less visible with age, especially hyperactivity. A restless child may grow into an adult who simply feels restless inside. The difficulties are still there, but they can look different.

The signs also need to have lasted for at least six months, so a short period of stress or poor sleep isn't mistaken for ADHD.

ADHD is a neurodevelopmental condition, which means it begins in childhood. For a diagnosis, several signs need to have been present before the age of 12.

This doesn't mean someone must have been diagnosed as a child. Many adults, particularly women and those with quieter, inattentive traits, were never recognised at school. Clinicians look back at school reports, family memories and personal experiences to understand what things were like back then.

Several signs need to be present in two or more settings, such as:

• home and school
• work and home
• friendships and social life

This helps clinicians tell ADHD apart from difficulties linked to one particular environment, such as a stressful job or a hard time with one teacher. It's also why children's assessments usually include information from both parents and school.

Having the signs isn't enough on its own. There must be clear evidence that they get in the way of, or reduce the quality of, everyday life. For example, they might affect:

• learning and progress at school or college
• keeping up at work
• relationships with family, partners or friends
• managing everyday tasks, like money, routines or appointments

Some people manage well on the surface but only by working much harder than others. A good assessment looks at the effort behind how things appear, not just the outcome.

Finally, the signs must not be better explained by something else. Anxiety, low mood, trauma, sleep problems and some other conditions can look similar to ADHD.

Sometimes, ADHD occurs alongside these conditions, or alongside autism. A specialist clinician will consider the whole picture, so that everything that's going on is recognised.

Depending on which signs are most noticeable, the DSM-5 describes three presentations:

• mainly inattentive, where difficulties with focus and organisation stand out
• mainly hyperactive-impulsive, where restlessness and impulsivity stand out
• combined, where both are present

Presentations can change over time. A child with combined ADHD may find that inattention becomes the main difficulty as they grow up.

Raiys works nationwide, offering online ADHD assessments for adults and for children and young people aged 5 to 17 across the UK. Our experienced, specialist ADHD team uses DSM-5 and ICD-11 criteria and follows NICE guidelines. We bring together questionnaires, information from people who know you or your child, and a detailed clinical interview, so the criteria are applied carefully and fairly.

If you're in crisis right now, call 999, go to A&E, or call Samaritans free on 116 123, any time of day or night.

Ready to take the next step? Find out more about our adult ADHD assessment or child ADHD assessment.

The criteria can look like a checklist, but a good assessment is never just about ticking boxes. It's about understanding the person behind them.