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How is ADHD Diagnosed?

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While the symptoms of attention deficit disorder (ADHD) may appear commonplace in many people’s behavior (as many symptoms for mental disorders are), there are a set of specific diagnostic criteria used by trained mental health professionals to make the diagnosis.

The official diagnostic criteria for ADHD state that the symptoms must occur beyond the extent that is normal for the person’s age, and must occur in a variety of different situations (e.g., not just school). For a diagnosis of ADHD, the symptoms must also have appeared before the age of 7 (for childhood ADHD), and have continued for at least 6 months.

Impairments due to the symptoms of ADHD must also have been observed in at least two different settings, such as at school, at work, in the community, at social events, or at home. For example, a child who is overly active in the playground but has no problems concentrating on their schoolwork may not be appropriate for a diagnosis of ADHD.

So the critical questions to consider before an ADHD diagnosis is made are whether the symptoms are: (a) excessive compared with what would be expected; (b) longer-term rather than in response to a recent change; and (c) pervasive rather than limited to one environment.

ADHD Diagnosed in Children

The signs of possible attention deficit disorder may first be noticed long before the child begins school. Their lack of attention, hyperactivity, and impulsivity may be seen when these lose interest in playing a game or watching a TV show, or if the child runs around and seems completely out of control. Parents may feel it is necessary to contact a pediatrician or a child psychologist to undergo an assessment of whether or not their child’s behavior is appropriate for their age. Often they will be reassured that the child is behaving within normal limits and is just unusually exuberant or a little immature for their developmental stage.

Sometimes it’s another adult who first suspects that a child may have attention deficit disorder, such as a babysitter or teacher. Teachers with experience of the disorder are particularly well-placed to identify the symptoms of ADHD, especially as the symptoms are particularly evident in the school environment when teachers have come to know how children “typically” behave. The inattentive form of ADHD may be missed for some time in pupils who are seemingly cooperative.

Once a specialist is consulted, the professional will begin to gather information on the child’s unusual behavior and rule out possible causes other than ADHD, for example:

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  • A sudden change in the child’s life, such as death of a close relative, divorce, or a parent’s job loss
  • Previously undetected seizures
  • Middle ear infection, which can cause hearing problems
  • Other types of medical disorder that may be affecting the child’s brain
  • Learning disability
  • Anxiety and/or depression

These factors can usually be ruled out with help from the parents and school, but tests may be necessary. Alongside this information, the specialist will find out how the child’s behavior is currently being handled, and look into the nature of the child’s home and school to find out if they are unusually stressful or chaotic.

The child will then be assessed directly, and their behavioral symptoms will be observed in a range of environments and compared against those set out in the diagnostic manual. The specialist will give special attention to the child’s behavior during situations which call for the most self-control, and noisy or unstructured situations such as parties. Their response to during needing sustained attention (reading, working math problems, or playing a board game) will be observed.

This data will allow the specialist to pieces together a profile of the child, finding out which specific ADHD symptoms the child shows, how often, and in which situations. Children with ADHD will vary on their age when symptoms began, the pattern of symptoms – whether they are chronic or come and go in phases, and the extent to which they interfere with aspects of the child’s life such as friendships, school activities, home life, and community activities.

Other related problems, if they exist, may also be identified during diagnosis.

The assessment will include speaking with teachers who have taught the child since they began school. Standard evaluation forms — known as behavior rating scales — are filled in by the teachers, rating their observations of the child’s behavior. Results are then compared with what would be considered “normal”.

Interviews also take place with the child’s teachers, parents, and possibly other adults who know the child well. They will be questioned on how the child behaves in many settings, and may be given a rating scale to mark the severity and frequency of the behavior.

Further tests that are often given include: social adjustment, mental health, intelligence, and learning achievement.

ADHD Diagnosed in Adults

Originally, attention deficit disorder was a strictly childhood disorder diagnosed only in children. Nowadays, experts no longer believe that the symptoms of ADHD disappear in adulthood. Figures suggest that up to two-thirds of children with the disorder will continue to display ADHD behaviors well into adulthood. As the individual grows up, he or she will become more aware of the challenges this brings.

But many adults with ADHD were never diagnosed with a problem in their early years, or were given the wrong diagnosis — such as a learning disability, attitude problem, or personality or character disorder.

Nevertheless, the disorder may be the underlying cause of many personal and work problems including difficult relationships, anger, depression, and alcohol or substance abuse. Once a proper diagnosis is made, the individual can begin to find their own way of coping, even using their excess energy in positive ways.

For adults, ADHD diagnosis involves examining the individual’s past as well as their current difficulties. Family members may be asked to help. The specialist will review and assess their childhood and recollections of behaviors that may fit the ADHD symptoms. Academic and job performance will be evaluated, as will family relationships and the nature and quality of the person’s friendships.

The specialist must be careful to rule out from a ADHD diagnosis adults who believe they have the disorder, but who seemingly had no problems in childhood. These individuals may need advice with their current issues, but the label of ADHD, and its recommended treatment, will probably not be helpful.

The basic symptoms of ADHD are the same for both adults and children. However, adults may also suffer from low self-esteem, an increased sense of frustration, and many problems caused by lack of focus and organisational skills. They may need further assessments to rule out mistaken diagnosis of other conditions, with which they may have been labeled for decades.

Following diagnosis, counseling may be of great help in understanding the impact of ADHD on their life. Certain drug therapies may be very beneficial, such as antidepressants for depression or anxiety.

After Diagnosis

Once a correct diagnosis is made, the child or adult with ADHD can now be given help to manage their condition. For parents of children with ADHD, adults with ADHD, and even the children themselves, diagnosis can be a relief because it helps explain behavior problems which may have occurred for a long time previously.

Now a new journey can begin in which the condition is explored and specific action taken. Educational, medical, and emotional support can be given, such as informing teachers, other staff at school, and other adults who often interact with the child. Lessons may need to be planned differently, and the most effective medication for the individual can be explored.

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This article is based upon a brochure published by the National Institute of Mental Health.

How is ADHD Diagnosed?

Ben Martin, Psy.D.

Ben Martin, Psy.D. is a clinical psychologist in private practice. He also writes psychoeducational articles about mental disorders and mental illness.

APA Reference
Martin, B. (2018). How is ADHD Diagnosed?. Psych Central. Retrieved on July 10, 2020, from
Scientifically Reviewed
Last updated: 8 Oct 2018 (Originally: 17 May 2016)
Last reviewed: By a member of our scientific advisory board on 8 Oct 2018
Published on Psych All rights reserved.