There is no single test used to diagnose ADHD. Experts diagnose ADHD when symptoms impact a person's ability to function and they've shown some or all of the symptoms on a regular basis for more than 6 months and in more than one setting.
To rule out other conditions, a doctor may ask for tests, including:
- Hearing and eyesight
- A blood test for lead levels
- A blood test for diseases such as thyroid disease
- A test to measure electrical activity in the brain
- A CT scan or MRI to check for brain abnormalities
Brain Wave Tests
The Neuropsychiatric EEG-Based Assessment Aid (NEBA) System is a scan that measures brain waves. The ratio of certain brain waves tends to be higher in children and adolescents with ADHD. The scan is approved for use in children ages 6 to 17, but is meant to be used as part of a complete medical and psychological exam.
Other tests help diagnose other medical conditions that mimic ADHD. But they don’t diagnose ADHD.
What Doctors Look For
To diagnose ADHD, doctors most often use guidelines established by the American Psychiatric Association. The group has identified three types of the disorder:
1. Inattentive type: A person must have at least six of these nine symptoms, and few symptoms of hyperactive-impulsive type:
- Doesn't pay attention to detail or makes careless mistakes
- Doesn't stay on task
- Doesn’t listen
- Doesn’t follow instructions or finish schoolwork or chores
- Trouble organizing tasks or activities
- Avoids or dislikes doing things that take effort or concentration
- Loses things
- Easily distracted
2. Hyperactive-impulsive type: A person must have at least six of these nine symptoms, and few symptoms of inattentive type:
- Fidgets or squirms a lot
- Gets up from their seat a lot
- Runs or climbs at inappropriate times
- Has trouble playing quietly
- Always “on the go” as if “driven by a motor"
- Talks excessively
- Blurts an answer before the question has been completed
- Trouble waiting their turn
- Interrupts others
3. Combined type. This is the most common type of ADHD. People with it have symptoms of both inattention and hyperactivity-impulsivity.
Along with these APA guidelines, health care professionals may also use rating scales to help them evaluate and track ADHD symptoms. A few examples are:
The Vanderbilt Assessment Scale. This 55-question assessment tool reviews symptoms of ADHD. It also looks for other conditions such as conduct disorder, oppositional-defiant disorder, anxiety, and depression.
The Child Attention Profile (CAP). This scale is generally filled out by teachers and tracks common ADHD symptoms.
Behavior Assessment System for Children (BASC). This test looks for things like hyperactivity, aggression, and conduct problems. It also looks for anxiety, depression, attention and learning problems, and lack of certain essential skills.
Child Behavior Checklist/Teacher Report Form (CBCL). Among other things, this scale looks at physical complaints, aggressive or delinquent behavior, and withdrawal.
Conners Rating Scale. This is a questionnaire that asks about things like behavior, work or schoolwork, and social life. They can show how these symptoms affect things like grades, jobs, home life, and relationships.
Diagnosing ADHD in Children
Health care professionals such as pediatricians, psychiatrists, and child psychologists can diagnose ADHD with the help of standard guidelines from the American Academy of Pediatrics or the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM).
You can also find a professional who specializes in ADHD diagnosis through your health plan, your child’s teacher or school counselor, other parents of children with ADHD, or nonprofit organizations such as Children and Adults with Attention-Deficit/Hyperactivity Disorder (CHADD).
The diagnosis involves gathering information from several sources, including schools, caregivers, and parents. The health care professional will consider how a child's behavior compares with that of other children the same age, and they may use standardized rating scales to document these behaviors.
Some symptoms that suggest ADHD in children include inattention, hyperactivity, and impulsivity. Many children with ADHD:
- Are in constant motion
- Squirm and fidget
- Make careless mistakes
- Often lose things (such as school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, and mobile phones)
- Do not seem to listen
- Are easily distracted
- Do not finish tasks
- Often leave their seat in situations when remaining seated is expected
- Often run about or climb in situations where it isn’t appropriate (adolescents or adults may be limited to feeling restless)
- Can’t play or take part in leisure activities quietly
- Talk excessively
- Blurt out an answer before a question has been completed
- Have trouble waiting for their turn
- Interrupt or intrude on others (e.g., butting into conversations or games)
- Have trouble organizing tasks and activities
- Forget daily activities
To diagnose ADHD, your child should have a full physical exam, including vision and hearing tests. Also, they'll probably be tested with the NEBA System.
The evaluation may also include interviewing you, your child's teachers, and any other adults who are a big part of your child's life. The evaluator may ask each of you to fill out standardized forms, known as “behavior rating scales,” to rate different aspects of your child’s behavior. These scales may also be used later to track progress with treatment.
The health care professional should take a complete medical history to check for other conditions that may affect a child's behavior. Certain conditions that could mimic ADHD or cause ADHD-like behaviors are:
- Recent major life changes (such as divorce, a death in the family, or a recent move)
- Undetected seizures
- Thyroid problems
- Sleep problems
- Lead toxicity
Though many children show some of the behaviors for ADHD, they do not necessarily have the disorder. An ADHD diagnosis requires that these behaviors have been persistent for at least 6 months, that some symptoms began before age 12, that symptoms are present in two or more settings (such as school and home), and that they significantly affect the child in at least two places (social life, school, etc.).
Diagnosing ADHD in Adults
It isn’t easy for a health care professional to diagnose ADHD in an adult. Sometimes, an adult will recognize the symptoms of ADHD in themselves when their child is diagnosed. Other times, they will seek professional help for themselves and find that their depression, anxiety, or other symptoms are related to ADHD.
In addition to symptoms of inattention and impulsiveness, adults with ADHD may have other problems, including:
- Chronic lateness and forgetfulness
- Poor organizational skills
- Low self-esteem
- Employment problems
- Short temper
- Hard time finishing a task
- Unthinking and immediate response; hard time controlling behavior
If these difficulties are not managed appropriately, they can cause emotional, social, occupational, and academic problems in adults.
In order to be diagnosed with ADHD, an adult must have persistent, current symptoms that date to childhood. ADHD symptoms continue as problems into adulthood for up to half of children with ADHD. For an accurate diagnosis, the following are recommended:
- A history of the adult's behavior as a child
- An interview with the adult's life partner, parent, close friend, or other close associate
- A thorough physical exam that may include neurological testing
- Psychological testing
ADHD Online Tests
If you think you may have ADHD, you can take tests online that compare your symptoms to those of the condition. Most are a few simple questions that ask you about different behaviors and how often you might have them. They can’t give a diagnosis, but they can tell you if you should see a professional for an assessment. If you do have ADHD, that knowledge can help you take the first steps toward controlling your symptoms.
You can take an online ADHD test for adults from ADDitude, a WebMD partner.
Disparities in ADHD Diagnosis
Researchers have found that the number of diagnosed cases of ADHD has climbed dramatically since the late 1990s. One recent study found that the condition affects as many as 1 in 10 children.
But some groups are less likely than others to get a diagnosis of ADHD or more likely to be misdiagnosed. Studies have found that members of racial and ethnic minority groups are less likely than white people to receive an ADHD diagnosis or to get treatment. There are many reasons why this happens, including:
- Different expectations of behavior for different groups
- Fear of stigma
- Financial barriers to screening and care
- Bias by health care professionals
Girls are much less likely than boys to be diagnosed with ADHD. This may be because they often have the inattentive form of the disorder, so their symptoms can be overlooked by parents and teachers. They may be diagnosed with another condition such as depression or anxiety and not get an ADHD diagnosis until they’re adults.
Managing the Costs of ADHD Diagnosis
An accurate diagnosis of ADHD can mean many tests with a specialist. Because of this, getting one can be an expensive process. Many insurance companies will not cover these costs or will cover them only in part. But resources are available to help you find lower-cost options for testing and treatment. You can find information about insurance benefits and financial help, as well as online support groups, through the advocacy group CHADD (Children and Adults with Attention-Deficit/Hyperactivity Disorder).
If your child is having trouble in school with learning and behavior, they may qualify for testing through their school or school district. You’ll need to submit a request in writing. If your child’s symptoms are found to have a serious impact on your child’s ability to learn, your child may be evaluated for ADHD as well as other learning disabilities.
ADHD screening may be available in your area for a reduced cost through a clinic associated with a hospital, county health service, or a college or university. A clinical research program may enroll children or adults for ADHD studies. Your doctor may be able to help you find a study, or you can find information through the National Institute of Mental Health.