How is ADHD diagnosed?

Photo of a boy at the doctor's

The number of children and teenagers being diagnosed with ADHD has been continuously increasing in recent years. Experts disagree on whether this is a good or a bad thing. On the one hand, it's important to take ADHD seriously. On the other, people shouldn't be diagnosed with this disorder for no good reason.

Compared to others their age, children and teenagers with attention deficit hyperactivity disorder (ADHD) are particularly inattentive, impulsive or hyperactive. This kind of behavior is quite normal up to a certain level. When diagnosing ADHD, it's important to determine when such behavior can be considered to be out of the ordinary. In order to avoid mistakenly classifying children as being ill, experts have agreed on certain criteria for diagnosing ADHD. It can be diagnosed with certainty only in children three years of age and up.

Two different sets of criteria have been developed. The diagnostic criteria developed by the World Health Organization are described in the “International Classification of Diseases (ICD).” The criteria developed by the American Psychiatric Association – the biggest psychiatric association worldwide – are described in the “Diagnostic and Statistical Manual of Mental Disorders (DSM).” The DSM criteria aren't as strict as the ICD criteria. This means that more children are diagnosed with ADHD if the DSM criteria are used.

What is meant by inattentiveness, hyperactivity and impulsiveness?

The two sets of diagnostic criteria largely agree on the meaning of inattentiveness, hyperactivity and impulsiveness.

Children and teenagers are considered to be inattentive if they

  • make a lot of careless mistakes when carrying out tasks at school or at home, or often fail to pay close attention to details.
  • find it difficult to concentrate on one thing for longer amounts of time, while playing or doing something else.
  • often do not listen in class or when someone is talking to them.
  • often do not complete tasks or activities. For instance, they may not do all of their homework, or stop playing a game with other children before it is finished.
  • find it hard to organize chores and their day-to-day lives.
  • really dislike and avoid chores that require longer periods of concentration.
  • often lose things that they need for school or their apprenticeship, such as pens, school books or tools.
  • are often distracted by things around them.
  • are very forgetful in everyday life.

Children and teenagers are considered to be hyperactive if they

  • are often restless, fidget with their hands or feet, or squirm in their seats.
  • often get up from their chair, even when they are expected to stay seated, for example during a school lesson.
  • often run around or climb on things when it is inappropriate (in children).
  • often feel restless (in teenagers).
  • find it difficult to be quiet during school lessons or leisure activities.
  • are always on the go, or seem to be “driven by a motor.”

Children and teenagers are considered to be impulsive if they

  • regularly interrupt other people, bursting in on conversations or games.
  • often blurt out answers to questions before people have had a chance to finish asking them.
  • find it difficult to wait their turn.

Which criteria are important for the diagnosis?

Based on the ICD criteria, a person is diagnosed with ADHD if

  • they show at least six signs of inattentiveness and three signs of hyperactivity and one sign of impulsiveness, and
  • they already started behaving in this way before the age of seven.

Based on the DSM criteria, a person is already diagnosed with ADHD if

  • they show at least six signs of inattentiveness or at least six signs of hyperactivity and impulsiveness, and
  • they already started behaving in this way before the age of twelve.

With both the ICD criteria and DSM criteria, ADHD is only diagnosed if the following is true too:

  • the behavioral problems have been observed for at least six months,
  • the behavior occurs in more than one setting, for instance at school and at home,
  • the behavior has a big negative impact on the child or teenager’s everyday life, for example their performance at school, their family life or friendships, and
  • other mental illnesses have been ruled out as possible causes of the behavioral problems.

For ADHD to be diagnosed based on the ICD criteria, the behavioral problems need to have started at a younger age than they do based on the DSM criteria. The ICD criteria also state that a person needs to show all three types of behavior (hyperactivity, impulsiveness and inattentiveness). As a result, if the ICD criteria are used, children and teenagers are only diagnosed with ADHD if they have severe behavioral problems. If the DSM criteria are used, children who have mild or moderate behavioral problems are diagnosed with ADHD too.

There is no clear agreed-upon definition of mild, moderate and severe ADHD.

The two sides of the diagnosis

Children and teenagers with ADHD have difficulties building up relationships with other people, and often don't perform as well as they could do at school or in apprenticeships. To be able to make use of the support and treatment options, it is important to get a correct first.

But it's also important to make sure ADHD isn't diagnosed too readily. A very thorough assessment is needed. If children or teenagers are wrongly diagnosed with ADHD, it can affect their self-confidence and self-esteem. They may get caught up in a vicious cycle, where their performance in school suffers because they think others believe they are less intelligent and less capable.

Being diagnosed with ADHD affects different families in different ways. Some are relieved to finally have an explanation for the behavioral problems. Others find it hard to accept the , feel they have been unfairly labeled or doubt that their child really has ADHD.

Preventing misdiagnosis

Some children and teenagers have a mild form of ADHD, where it is not clear whether their behavior is normal or whether treatment may be needed. It can be hard to make a in such cases. It usually takes several appointments, involving in-depth talks with the child or teenager and their parents. Ideally, information about their behavior at school or in kindergarten should be considered too. The assessments may include an observation of their behavior as well.

It's also important to take the official diagnostic criteria seriously. One study carried out in Germany suggests that many ADHD diagnoses are not reliable:

  • On the one hand, only 29% of children and teenagers who had been diagnosed with ADHD actually met the DSM criteria for ADHD.
  • On the other, only 43% of children and teenagers who met the DSM criteria had been diagnosed with ADHD.

It's very important to consider the child’s age when making the . The younger a child is, the more normal “immature” and impulsive behavior is. Several studies have shown that children who are among the youngest in their class when they start school are more often diagnosed with ADHD than children who are among the oldest. This is probably not because ADHD is more common in the younger children. Instead, they are simply less mature than the older children in their class, and may seem to be more impulsive because of this.

Increase in ADHD diagnosis

In 2006, ADHD was diagnosed in 2.3% of children and teenagers insured by the German statutory health insurer “AOK.” By 2014 this had doubled to 4.6%. Recent findings confirm that this trend has continued to 2021.

Some experts see the increase in ADHD diagnoses as a positive development. They assume that teachers, doctors and therapists are simply more aware of ADHD nowadays, and that too little attention was paid to it in the past. But others worry that behavior that is actually normal for children and teenagers is now considered to be abnormal, and that ADHD is too readily diagnosed.

It is not clear why more people are being diagnosed with ADHD nowadays. More is known about ADHD, and people are more aware of it than they used to be. Parents might also be more likely to seek medical or psychological help, and do so sooner. Teachers often encourage parents to get help too.

According to some experts, another reason for the increase in cases of ADHD is because the DSM diagnostic criteria changed in 2013: One of the current criteria is that the typical behavioral problems need to have started before the age of twelve. The cut-off age used to be seven years.

Last but not least, ADHD treatment is a lucrative business for the pharmaceutical industry. Some experts believe that more people are being diagnosed with ADHD because the manufacturers of ADHD medication have increased public awareness of the condition in order to increase their sales. But it's not easy to say how often medication is prescribed although it is not needed.

The public debate about ADHD is not about whether or not ADHD exists. Most experts agree that it does. The discussion is more about what type of behavior is considered to be a problem that needs to be treated, and which social developments and interests influence this. One thing is for sure, though: If a child has ADHD and it's having a negative impact in everyday life, it should be taken seriously.

Bruchmüller K, Margraf J, Schneider S. Is ADHD diagnosed in accord with diagnostic criteria? Overdiagnosis and influence of client gender on diagnosis. J Consult Clin Psychol 2012; 80(1): 128-138.

Deutsche Gesellschaft für Kinder- und Jugendpsychiatrie, Psychosomatik und Psychotherapie (DGKJP), Deutsche Gesellschaft für Psychiatrie und Psychotherapie, Psychosomatik und Nervenheilkunde (DGPPN), Deutsche Gesellschaft für Sozialpädiatrie und Jugendmedizin (DGSPJ). Langfassung der interdisziplinären evidenz- und konsensbasierten (S3) Leitlinie "Aufmerksamkeitsdefizit- / Hyperaktivitätsstörung (ADHS) im Kindes-, Jugend- und Erwachsenenalter" (in Überarbeitung, gültig bis 01.05.2022). AWMF-Registernr.: 028-045. 2018.

Kazda L, Bell K, Thomas R et al. Overdiagnosis of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents: A Systematic Scoping Review. JAMA Netw Open 2021; 4(4): e215335.

Roick C, Waltersbacher A. Hyperkinetische Störungen bei Kindern und Jugendlichen in Deutschland: Administrative Prävalenz und regionale Unterschiede in der Diagnosehäufigkeit. Psychiatr Prax 2015; 42(1): 21-29.

Thomas R, Mitchell GK, Batstra L. Attention-deficit / hyperactivity disorder: are we helping or harming? BMJ 2013; 347: f6172.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on June 21, 2022
Next planned update: 2025


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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